Facebook
When you shop through links on our site, we may earn an affiliate commission. This educational content is not intended to be a substitute for professional medical advice.

Ovulation 101: Understanding Ovulation & Fertility

Medically Reviewed by Caitlin Goodwin, MSN, RN, CNM
Updated
Your guide to understanding ovulation and the fertile window.

Are you trying for a baby and want to know when you’re most fertile? Or maybe you want to use ovulation as a means of birth control. Whatever the reason, you need to start by understanding ovulation.

Let’s find out what ovulation is, when it happens, how you can track it, and answer some frequently asked questions.


What Is Ovulation?

Ovulation is one part of a woman’s menstrual cycle. It happens when an ovary releases an egg which might then be fertilized by sperm. Whether it’s fertilized or not, it then travels down the fallopian tubes to the uterus.

If it’s been fertilized then it can implant in the uterus, which has prepared a lining ready for it. That is the start of a pregnancy. If not, then the lining of the uterus falls away and the egg and lining are discharged as we have our period.

When Does Ovulation Occur?

The timing of ovulation is not an exact science. In general, it happens somewhere between 11 and 21 days after the first day of your last period. This assumes that you have a 28-day cycle, with the first day of your period being “day one.”

For some women, it might be earlier, and for others, later. Every woman is different and even every menstrual cycle can be different for the same woman.

However, as the best estimate, it happens in the middle of your menstrual cycle, so around “day 14”.

There are various methods you can use to track when you ovulate, which we will detail in a moment.

Where Does Ovulation Happen?

Every woman is born with all the eggs they will have in a lifetime — our body does not make any more. There are somewhere between one and two million at birth and this number decreases to about 300,000 by the time puberty is reached.

How fantastic is that? If you get pregnant with a daughter, you will essentially have one-half of your grandbabies (their eggs) inside you!
Headshot of Caitlin Goodwin, MSN, RN, CNM

Editor's Note:

Caitlin Goodwin, MSN, RN, CNM

During the time a woman can reproduce, about 500 of the remaining eggs will be released during ovulation. The rest will die gradually when menopause occurs (1).

Each month, from the time a woman starts menstruating, an egg is released from the ovaries into the fallopian tube. The follicles in our ovaries begin to mature every month, between about days six to 14 of our menstrual cycle. The egg develops inside the follicle and is finally released in the middle of the menstrual cycle.

There are finger-like ends on the fallopian tube (fimbriae) that sweep across the top of the ovary. Small, hairlike projections, called cilia, then move the egg along the fallopian tube towards your uterus (2).

How Long Does Ovulation Last?

It’s down to those hormones again. Between about the sixth and 14th day of your cycle, the follicle-stimulating hormone (FSH) signals the egg inside the ovary to mature and get ready for release.

When the egg is mature, a surge of LH triggers the egg’s release. Ovulation happens during the 24 to 36 hours following this hormone surge and the egg lasts for approximately 24 hours (3).

The Fertile Window

The fertile window refers to the period in your monthly menstrual cycle when you may become pregnant. This is limited to about five or six days each month for most women.

To get pregnant, a mature egg will have been released from one of your ovaries. After release, the egg begins its journey along the fallopian tube, toward the uterus or womb. If it meets a viable male sperm along the way, then it can become fertilized.

The mature egg only lives for between 12 and 24 hours, so you basically have a limited window in which fertilization can happen. The good news here is that male sperm can live for up to five days in a woman’s body so it can lie in wait for your egg to release.

So, while ovulation is a one-day wonder, if you have had unprotected sex in the days leading up to ovulation, you can still get pregnant. This means you don’t need to have sexual intercourse on the exact day of ovulation in order to conceive.

Putting it in perspective, if you ovulate on day 14 of your monthly cycle, the egg is viable for fertilization until day 15. Your fertile window will have started at about day nine of your cycle as the sperm can live for five days. This gives you about a six-day fertile window each month.

How to Track Ovulation

Once you know and can recognize when you ovulate, then you can plan sexual activity to improve your chances of getting pregnant.

There are several methods you can use to track your ovulation. However, the only way to do it with 100 percent accuracy is with an ultrasound scan (4).

Even when using methods to track ovulation, the best chance of getting pregnant is to have sex regularly. This is about every two to three days throughout your cycle and every other day during your fertile window. This will ensure there is sperm ready and waiting in the fallopian tubes when a mature egg is released.

Let’s delve into some of the methods you can use to track ovulation.

1. Menstrual Charts

Tracking the length of your menstrual cycle each month can give you an indication of when you are most fertile. You will, however, need to keep a chart for several months for the data to be useful. There are apps that are gaining in popularity that many women use to track their cycle (5).

Each cycle can be different by a day or so, or more for some. For that reason, if your periods are irregular and your cycle differs a lot each month, this method won’t be the most accurate for you. It can also be time-consuming and a little complicated.

Grab A Calendar

To work out your fertile window, you will need to use a calendar to record your menstrual cycle each month. Day one of your period is the start of your cycle.

Once you have the details of a few months of your cycle, you need to subtract 18 days from the shortest cycle. This is the first day of your fertile window. If your shortest cycle is 28 days, that will be day 10.

Keeping in mind you have a six-day window, then subtract 11 days from your longest cycle. This gives you an indication of the last day of your fertile window. So if your longest cycle was 30 days, then this would be day 19.

Having sex every other day in between these dates will give you the best chance of conceiving (6).

Pros

  • Inexpensive.
  • Easily accessible.
  • Simple to calculate.

Cons

  • If your cycle is irregular, this method is likely to be too inaccurate to be useful.
  • It can take months of tracking to get a good handle on your fertile window.

2. Basal Body Temperature

Your basal body temperature (BBT) is the temperature of your body when at complete rest when you wake in the morning. This means before you get out of bed, go to the bathroom, or even roll over and cuddle your partner.

So how does ovulation affect it? When you ovulate, the levels of progesterone in your body increase, causing your temperature to rise by about 0.5 to 1 degree.

Your temperature will then remain at a higher level until your period begins. If it remains high past this date, then you could be pregnant.

The Equipment

You will need an accurate basal thermometer, to within one-tenth of a degree for Fahrenheit or one-hundredth of a degree for Celsius. There are some fancy options on the market, but a basic glass thermometer will work.

There are a few rules you will need to follow. For starters, you must take your temperature at the same time every day, give or take 30 minutes either way.

You must use the same thermometer, have had three or four hours sleep before waking and make sure it’s the first thing you do. That means no getting up, no peeing, before that temp is read.

There are several free charts available online that you can use to record your temperature (7). Alternately, you can use graph paper and make your own, charting the days on the horizontal line and the temperature on the vertical.

You need to start recording your temperature on the first day of your period. Note the time as well as your temperature. When you see an increase in your temperature for three days in a row, then the chances are you ovulated the day before the spike.

These charts can help you estimate on which day of your cycle you are most likely to ovulate over time. Over a 3-month period, you might see ovulation happening between days 11 and 14. You can then plan the best time to have sex to get pregnant as between days six and 15 (8).

Pros

  • Inexpensive.
  • Charts are easily available.
  • Results can be used by a fertility specialist if you aren’t conceiving.

Cons

  • You must be consistent and accurate.
  • The charts only give you an estimate of when you ovulate.
  • They need to be kept for several months to see a pattern emerge.
  • There are many factors that may interfere with an accurate BBT reading like alcohol consumption, staying up late or a restless night’s sleep, stress, travel, or illness.

3. Ovulation Kits

These kits are able to detect hormones that indicate you might be about to ovulate. We mentioned the luteinizing hormone (LH) earlier, and it’s a spike in this that these kits detect. It generally happens between 24 and 36 hours before ovulation.

Some kits also detect estrogen levels, which again rise before the LH surge takes place. These hormones can be detected in your urine. Some kits will be similar to a pregnancy test, where you pee on a stick and the result shows in a window.

Others will be strips you can dip in urine. Just make sure you fully read the instructions for the kit you have before using it (9).

Knowing when to start testing each month can be a challenge. These kits tend to have between five and seven days worth of tests. You might need to keep either menstrual charts or BBT charts to help you pinpoint the best time to test.

Pros

  • Easy to use.
  • Don’t need to use first thing in the morning, so they’re more flexible.

Cons

  • Can be expensive if used over some time.
  • Might be difficult to read if your LH surge is not high.
  • May give false-positive results if you have polycystic ovary syndrome.
  • Do not confirm ovulation, just that your body is trying to ovulate.

4. Fertility Monitors

These are handheld devices, which use levels of hormones in either saliva, cervical mucus, or urine to predict ovulation. They detect changes in estrogen and LH and display your most fertile time on a screen.

Fertility monitors differ from ovulation kits in that they record the information for you and retain it.

They can give you up to seven days’ notice of when you are likely to ovulate, depending on which brand you choose. Some of these devices are between 93 and 99 percent accurate (10).

Pros

  • Can detect three different hormones.
  • Can give up to seven days’ notice before ovulation.
  • Simple to use.

Cons

  • Can be expensive.

5. Charting Cervical Mucus

If you’re unsure how to check out your cervical mucus, rest assured that it’s not difficult. Before or after urinating (or both), wipe with toilet tissue and look to see what the mucus looks like. You should be able to see the color and consistency easily on the toilet paper.
Headshot of Caitlin Goodwin, MSN, RN, CNM

Editor's Note:

Caitlin Goodwin, MSN, RN, CNM

Some of our bodily fluids, like cervical mucus, can also give you an indication you might be ovulating.

Glands found in and around your cervix secrete mucus. The changes in hormones during your menstrual cycle affect the consistency and amount of this mucus.

This mucus serves to prevent things like bacteria entering the womb from the cervix. It also helps sperm on its journey into the uterus. Fertile cervical mucus can indicate you are about to ovulate.

How You Can Tell

Your vaginal discharge at this time will resemble raw egg whites. Checking your vaginal discharge will help you recognize the changes.

Some might be a bit squeamish about looking at and touching this discharge, but it’s only a part of your normal bodily fluids. It will change from dry and sticky, to creamy, then wet and watery, and finally wet and stretchy, like an egg white.

The creamy and wet watery stages warn you ovulation is coming (11).

It is worth noting, however, that not all women will experience wet, stretchy mucus when ovulating.

Pros

  • Does not need any testing kits.
  • It’s free.

Cons

  • Can be confused with semen.
  • Can take some time to recognize the changes.
  • Only indicates that ovulation might be close.

6. Saliva Ferning

Saliva is another bodily fluid that might indicate that ovulation is close. The levels of estrogen in the body increase and this can affect the amount of salt in our saliva. When the saliva dries, these higher amounts of salinity can be seen as a “fern pattern” through a microscope.

You can buy kits which contain a small microscope and the glass slides you need to check your saliva (12).

However, this technique may be unreliable (13). There are many things that can affect the ferning patterns which need to be taken into account. These include everyday acts, such as eating, drinking, and brushing your teeth. Consequently, this method should be used in conjunction with some of the others for it to be of use (14).

Pros

  • Saliva samples are quick and easy to obtain.
  • Can be a useful addition to other ovulation tracking methods.

Cons

  • Can take some practice to interpret the results.
  • Not as reliable as some other methods of tracking ovulation (15).

Ovulation Symptoms

There are some symptoms and signs that can be associated with ovulation. Some of these are also similar to those experienced when you are premenstrual or when you are pregnant.

Not all women will experience some or all of these symptoms, however. Things to look out for include:

1. Breast Tenderness

Pain in your breasts can be linked to your menstrual cycle. This is called mastalgia and is nothing to worry about. It is thought to be caused by the hormone changes women experience at this time of the month.

The pain can be mild and you might barely notice it. On the other hand, it can be severe and you won’t want to wear a bra or other tight clothing. You also might not want your breasts to be touched.

The pain may be felt in one or both breasts, or it could feel like it’s radiating under your arm (16).

2. Light Spotting or Vaginal Discharge

Spotting or light bleeding might be experienced by a small number of women around the time of ovulation. It will appear as a light pink or red in color and could be mixed with cervical mucus. It will generally only last for one or two days and will appear around the middle of your cycle.

Again, it’s those hormones that are thought to be the culprits. The rapid changes in progesterone and luteinizing hormone could cause this to happen.

There are other times you might experience spotting throughout your cycle and it’s important not to get these confused. Some women experience what is called an implantation bleed, when a fertilized egg attaches to the uterus.

Is That Common?

About 33 percent of women who get pregnant will have an implantation bleed or spotting.

The timing of this spotting is different, but it will generally happen a few days before your next period is due. The bleeding will be light pink to dark brown and last for a day or so. It will be much lighter in flow than you would see during a period.

Menstrual bleeding is usually bright to dark red, with a steady flow, and lasts for a few days or more (17).

3. Ovulation Pain

Pain can sometimes be felt in the lower abdomen during ovulation in the middle of your cycle. Called mittelschmerz, the German word for middle pain, it generally doesn’t need medical attention. It can last anywhere from a few minutes or hours up to several days.

The pain can occur on one side in your lower abdomen. It can either feel like a dull cramp or might be sharp and sudden. It is not often severe, however, if it is and if it persists, seek medical advice.

As an egg is usually released from one ovary each month, the pain can move from side to side in each cycle. It might alternate, or could be the same side for a few cycles (18).

4. Changes in Sex Drive

Mother Nature steps in and encourages us to procreate at the time of ovulation. Changes in our hormones are likely to increase our libido leading up to ovulation, and then drop it again afterward.

Studies have shown the increase in estrogen and then the spike in luteinizing hormone are likely to make you want sex more.

But if you are depressed, stressed, or anxious, then you might not get this increased urge for sex (19).

5. Other Physical Symptoms and Signs of Ovulation

Bloating is another symptom that can be associated with ovulation. The hormone changes can cause water retention. This should only last a couple of days.

Menstrual migraines are yet another sign of ovulation, once more caused by the rise in estrogen (20).

There’s bad news for people with asthma. The fluctuating hormone levels can cause inflammation in the airways, exacerbating asthma symptoms (21).

For people with arthritis, symptoms might be less after ovulation and through your period. It’s thought the higher levels of estrogen and progesterone ease the symptoms (22).

Fatigue can be another sign of ovulation. Once an egg is released, the empty follicle triggers a rise in progesterone. This may make you feel more tired and sluggish than normal (23).

6. Super Senses

You may find near the time of ovulation that your sense of smell is a lot more acute. Scents will be more pronounced and your preferences might change (24).

7. Changes in the Cervix

Your cervix goes through changes throughout your menstrual cycle. There are times when it will extend lower in the vaginal canal and you’ll be able to feel it with your fingertips. Then there are other times when it will be sitting high and you might not be able to reach it.

It can also feel different and the opening into the uterus can change in shape. If you get friendly with your cervix, you can find out when ovulation is approaching.

How It Will Feel

It will be high and will feel moist and soft during your fertile window.

When this has passed, it will lower again. The opening of the cervix will also feel expanded during the fertile window, allowing the easy passage of sperm into the uterus (25).

Both the cervix and the vaginal passage have a fine balance of fluids to protect you from infection. Cervical mucus also protects and helps sperm move into the uterus. For these reasons, you should not practice douching (26).

You should avoid douching for a number of other reasons. While you may be trying to freshen your vagina, the opposite occurs. Douching can disrupt your vaginal pH and allow bacteria to flourish.
Headshot of Caitlin Goodwin, MSN, RN, CNM

Editor's Note:

Caitlin Goodwin, MSN, RN, CNM

8. Dental Issues

Problems with your teeth and gums are probably not things you would associate with ovulation. It’s back to those darn hormones again.

Despite maintaining good oral health, you could find the risk of swollen, red gums is increased around the time of ovulation (27).

9. Mood Changes

Yes, you guessed it, hormones are responsible once again. We know they are necessary but, boy, do they cause some problems as well.

The fluctuating levels of hormones during ovulation may make you feel moody, anxious, or down. For some women, this passes and might return around a week before your period is due. For others, it can be long-lasting and quite severe (28).


Headshot of Caitlin Goodwin, MSN, RN, CNM

Medically Reviewed by

Caitlin Goodwin, MSN, RN, CNM

Caitlin Goodwin MSN, RN, CNM is a Certified Nurse-Midwife, clinical instructor and educator. She has ten years of nursing experience and enjoys blogging about family travel and autism in her free time.