What Is Ovulation?

Ovulation occurs when a person’s ovaries release a mature egg. This usually happens about halfway through the menstrual cycle, on or about day 14. After ovulation, the egg travels from the ovaries to the fallopian tubes, where it can be fertilized if sperm is present. If an egg is fertilized and implants in the uterus, a pregnancy results. 

Knowing when you ovulate can help you get pregnant or avoid pregnancy. You are most likely to get pregnant if you have unprotected sex up to three days before, or within a day after, you ovulate. That’s because sperm can survive in the reproductive tract for days, but once an egg is released, there’s only a small amount of time that it can be fertilized in the fallopian tubes.

Learn more about ovulation and its role in pregnancy, below. 

Process

Ovulation occurs when an egg is released from the ovaries. The cycle begins on the first day of your period and lasts until the day before your next period. On average, a menstrual cycle lasts 28 days, although it can be longer or shorter. 

Ovulation occurs roughly in the middle of the cycle, or 14 to 16 days before the beginning of your period. Although most people with a uterus have two ovaries, only one egg is released each month in most circumstances. 

A person’s cycle includes two phases.

The follicular phase is the first half of the cycle when your body produces both follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

• FSH causes the growth of a number of ovarian follicles, each of which contains one egg. At some point, one follicle develops faster than the rest. This is the egg that will be released at ovulation.
• At that point, estrogen levels cause FSH levels to fall, so one follicle continues to develop.
• A surge in LH in the days before ovulation helps that egg mature, preparing it for potential fertilization.

The luteal phase is the second half of the cycle when the actual release of an egg from the ovaries occurs. This is typically 10 to 12 hours after LP peaks.

• At that point, the egg is picked up by the fimbriae tubae—the finger-like outcroppings of the fallopian tube—and begins its journey through the reproductive tract.
• If the egg is fertilized in the tube, it will move to the uterus and implant, resulting in pregnancy; if it’s not fertilized, it will disintegrate as it moves through the uterus. If the pregnancy does not implant in the uterus, that can lead to an ectopic pregnancy.

Signs of Ovulation

Some people experience subtle signs of ovulation, like bloating, pain on one side of the stomach, or spotting. Other ways to track ovulation track include:

• Changes in cervical mucus
• Basal body temperature
• At-home ovulation tests

Changes in Cervical Mucus

The cervix naturally produces mucus, which changes in color and consistency through the menstrual cycle. In the days before ovulation, your cervical mucus may increase in volume and take on an egg-white consistency.

Many people have a sensation of wetness during those days. After you ovulate, your cervical mucus will become sticky and cloudy looking, and there will be much less of it.

Basal Body Temperature

Another way of predicting ovulation is by tracking your basal body temperature.

Most people experience a small increase in their body temperature around ovulation. The change is very small—between 0.4 and 0.8 of a degree Fahrenheit. Because of that, in order to predict ovulation using temperature, you must buy a special basal body thermometer (which will measure temperature to two decimal places) and take your temperature every day at the same time, usually before you get out of bed.

At-Home Ovulation Tests

Many people use at-home ovulation tests, which track the LH surge, allowing you to know what are most likely your most fertile days.

According to one study, those using home tests do target intercourse effectively to the fertile window, and there is an increased likelihood of pregnancy with successful timing. Sex on the day preceding the LH surge—which is identifiable only by home tests that measure estrogen—significantly increases the likelihood of pregnancy.

Pregnancy

Knowing when you ovulate can help you become—or avoid getting—pregnant:

• If you are trying to get pregnant: The chances of pregnancy are highest if you have sex two to three days before you ovulate or on the day of ovulation.
• If you are trying to avoid getting pregnant: Using birth control is your best method of preventing pregnancy. Sperm can live for up to five days in the reproductive tract, so you’ll want to avoid unprotected sex for at least five days before ovulation and two days afterward.

When Ovulation Doesn’t Occur

Most people who experience a regular menstrual cycle ovulate. However, there are some times when you will not ovulate, including:

• During pregnancy
• If you are breastfeeding
• Being diagnosed with a medical condition that interferes with ovulation, like polycystic ovary syndrome (PCOS)
• Taking some forms of birth control

Assisted Reproduction

Some people—including those with PCOS—do not ovulate regularly. This can cause or contribute to infertility.

With assisted reproduction, medications can be used to stimulate the development of multiple eggs, which may be released during ovulation. Other medications that stimulate LH are then used to “trigger” ovulation to occur—these are known as trigger shots.

Insemination or sexual intercourse can be timed around ovulation, in order to increase the chances of pregnancy. 

A Word From Verywell

Understanding ovulation is a key part of taking care of your health. Knowing when you ovulate can help you get pregnant more quickly or avoid unwanted pregnancy. 

For most people, ovulation takes place around day 14 of their menstrual cycle. However, this can vary from person to person. Tracking signs in your body, like an increased amount of clear cervical mucus or a change in basal body temperature, can give you more accurate information on when you are ovulating.

Although there can be a learning curve to tracking your menstrual cycle and understanding when you ovulate, apps make it easier than ever to take charge of your fertility. You can also try to use an at-home ovulation test to increase your chances of accurately tracking ovulation.