When Do You Ovulate?

When some people hear the term “menstrual cycle,” they think of their menstrual period. But periods normally last only 5–7 days.

A woman's menstrual cycle is the monthly cycle of changes that the body goes through to prepare for the possibility of getting pregnant.

The release of an oocyte (immature egg) from the ovary is an essential part of this process.

The 101: What Is Ovulation?

During reproductive ages, the ovary releases an oocyte every month. This event occurs when ovary follicles rupture and release the oocyte which travels to the fallopian tube and becomes an ovum or egg. 

The rupture of the ovary follicles can cause some light spotting and some women can even feel it happen. However, for the vast majority of women, the moment of ovulation goes unnoticed.

The process of ovulation is controlled by the hypothalamus of the brain and through the release of hormones. This means that ovulation can be impacted by hormone levels and stressors.

From jet lag to thyroid disorders, the sensitive process of ovulation can be disrupted when your body undergoes changes. Hormonal contraceptives inhibit ovulation to prevent pregnancy. 

When Does Your Menstrual Period Come In?

After the oocyte is released from the ovary, it moves into the fallopian tube. At this point it is called an ovum or egg. The egg stays in the fallopian tube for about 24 hours, waiting for a single sperm to fertilize it.

If the mature egg is not fertilized during that time (i.e., pregnancy doesn’t occur), it disintegrates (breaks down) and menstruation (your next period) begins 11–16 days later.

Ovulation and Fertility: The Fertile Window

For many women, ovulating is an unnoticed process. However, for women hoping to get pregnant, knowing when you might be ovulating is important.

Your most fertile days (the “fertile window") are the 5 days leading up to and including ovulation. The fertile window is when you’re most likely to conceive and have the greatest chance of getting pregnant. 

So, having sexual intercourse during your fertile window (your most fertile days) gives you the best chance of ensuring the sperm is present when the egg is released so that you can successfully become pregnant.

It’s worth noting that many women do not have an average cycle length of 28 days. And even if they don't have irregular cycles, when you ovulate can be impacted by many factors, from stress and jet lag to smoking and illness. 

Moreover, nutrition, smoking, and seasonal changes can also impact ovulation and therefore fertility. So, rather than thinking in terms of day X of your cycle, look for the ovulation symptoms described below to identify your fertile days.

This is one of the reasons birth control doesn’t just focus on ovulation. When the realities of life kick in, the fertile window can be a bit of a moving target. As we all know, our bodies don’t always follow the rules ;)

When Does Ovulation Occur in the Menstrual Cycle?

Every woman’s cycle is different. Some of us have longer periods or menstrual cycles than others, for example.

But generally a woman’s entire menstrual cycle is an average length of 28 days. That said, it can range between 21 to 35 days in adults and from 21 to 45 days in young teenagers. That's why most women track their menstrual cycles and cycle length with a period calculator or diary.

The first day of a menstrual cycle is counted from the first day of your period. You ovulate about 14 days before your period starts.

If your average menstrual cycle is 28 days, ovulation occurs around day 14, and your most fertile days are days 12, 13, and 14. 

If your average menstrual cycle is 35 days ovulation happens around day 21 and your most fertile days are days 19, 20, and 21.

What Are the Telltale Signs of Ovulation?

Your Basal Body Temperature Falls

Your basal body temperature drops a little bit just before your ovary releases an egg. Then, 24 hours after the egg's release, your basal body temperature rises and stays up for several days. 

According to Healthlink BC your temperature averages between:

• 36.1°C (97°F) to 36.4°C (97.5°F) BEFORE ovulation  and
• 36.4°C (97.6°F)  to 37°C (98.6°F) AFTER ovulation 

"To use the basal body temperature method: Take your basal body temperature every morning before getting out of bed. Use a digital oral thermometer or one specifically designed to measure basal body temperature. Make sure you get at least 3 hours of uninterrupted sleep each night to ensure an accurate reading," the Mayo Clinic suggests.

"For the most accurate results, always take your temperature using the same method. Try to take your temperature at the same time each day, when you first wake up."

Cervical Mucus Changes When You Ovulate

The changes in your discharge over the course of your menstrual cycle also hold clues about when you might be ovulating.

If your cervical mucus is...

• Dry or sticky: It’s unlikely you’re ovulating
• Creamy: Ovulation may be coming
• Wet or watery: Ovulation may start soon
• Wet and stretchy (egg white texture): You may be ovulating

It’s worth noting that cervical mucus is just one component of vaginal discharge, which can also include vaginal lubrication, arousal fluid, and more.

Again, making such observations is not an exact science and no woman’s body is a clock. But if you keep a period diary and ovulation calendar, it might be worthwhile to also note any observable changes to cervical mucus. Over time, you may see a pattern emerge.

Your Cervix Softens and Opens Up

As you approach your most fertile time, your cervix softens. This is sometimes known as having a short, high, open, and wet cervix (SHOW). 

For a step-by-step guide to checking your cervix position, visit this guide on Flo’s website. 

You May Experience Slight Twinge or Cramping

They say there’s a word in German for everything. Well, here’s proof: Mittelschmerz. It translates literally as “middle pain” and is the name for the slight twinge or cramp that some women experience when the follicle releases the oocyte.

For many women, there is no sensation whatsoever. 

If there is a sensation, the pain will occur on one side of your lower abdomen. Because you have ovaries on 2 sides, the pain will switch sides each month, distinguishing it from the uterine cramping associated with menstruation.

According to the Mayo Clinic, “Mittelschmerz pain occurs on the side of the ovary that's releasing an egg (ovulating). The pain may switch sides every other month, or you may feel pain on the same side for several months. 

“Keep track of your menstrual cycle for several months and note when you feel lower abdominal pain. If it occurs mid-cycle and goes away without treatment, it's most likely mittelschmerz.”

If the pain is more severe, you should seek medical advice from a healthcare professional.

Some Light Spotting May Occur When You Ovulate

When the ovaries release the oocyte, a tiny follicle ruptures to allow it to be released. This can be a cause of spotting for a day or so.

For some women, spotting that occurs around the time of ovulation is light red or pink in color. This is because we also produce more cervical fluid around the time of ovulation and the blood gets mixed with that cervical fluid, causing it to be a lighter shade.

Increased Libido or Sex Drive

The most well-known sign of ovulation is an increased sex drive. It’s important to note that this does not mean you’ll only want to have sexual intercourse during ovulation. But it may definitely mean that you may experience an increased libido.

According to a report on Psychology Today, “ovulating women do clearly increase their sexual desire, and they do increase the frequency with which they have sex with their current partners.”

How Long Do You Ovulate For?

Ovulation lasts between 12 and 24 hours. That's how long the egg released by the ovary is viable for fertilization.

How to Know Your Fertile Window: Ovulation Test Kits

In addition to tracking the signs of ovulation listed above, there’s another step you can take to predict ovulation: Ovulation predictor kits. 

This is especially helpful for those who need to identify the fertile window and understand their reproductive health, such as people struggling with getting pregnant or using fertility awareness-based methods.

The Importance of Luteinizing Hormone

An ovulation kit (also sometimes called an OPK, which stands for ovulation predictor kit) is a test that detects the presence and concentration of luteinizing hormone (LH) in your urine. Between 12–48 hours on average before ovulation, there is a brief surge in luteinizing hormone levels. Then, hormone levels drop. 

Ovulation kits may be especially helpful for women trying to get pregnant but have irregular cycles. However, the body can find ways to fool such methods...

According to the American Pregnancy Association, “When taken correctly, ovulation tests are approximately 99% accurate in detecting the LH surge that precedes ovulation. However, these tests cannot confirm whether ovulation actually occurs a day or 2 later. 

“Some women may have a surge in the LH hormone without releasing an egg. This condition is known as luteinized unruptured follicle syndrome (LUFS).”

Your Ovulation Calculator

Learning when you ovulate means yo can predict when you’re likely to be fertile. More generally, using an ovulation calculator helps you become more familiar with your own body and your cycle’s length.

This can help you appreciate the wondrous complexity of your body, but also notice any changes that might need medical attention.

Written by Jane Flanagan — Updated on April 5, 2022.

We hope you found this post informative — but remember: we’re not doctors and this post is not medical advice! While all posts are fact-checked and well researched, we always recommend you chat with your doctor about any questions or concerns you might have regarding a medical condition. We’re here to support and educate, but never with the aim of disregarding professional medical advice you’ve been given. Phew, now that that’s out of the way, you can go on living unapologetically free.