Ovulation is a part of your menstrual cycle. It occurs when an egg is released from your ovary.

When the egg is released, it may or may not be fertilized by sperm. If fertilized, the egg may travel to the uterus and implant to develop into a pregnancy. If left unfertilized, the egg disintegrates and the uterine lining is shed during your period.

Understanding how ovulation happens and when it takes place can help you achieve or prevent pregnancy. It can also help you diagnose certain medical conditions.

Ovulation typically happens around day 14 of a 28-day menstrual cycle. However, not everyone has a textbook 28-day cycle, so the exact timing can vary.

In general, ovulation occurs in the four days before or four days after your cycle’s midpoint.

The process of ovulation begins with your body’s release of follicle-stimulating hormone (FSH), typically between days 6 and 14 of your menstrual cycle. This hormone helps the egg inside your ovary to mature in preparation to release the egg later.

Once the egg is mature, your body releases a surge of luteinizing hormone (LH), triggering the egg’s release. Ovulation may happen in the 28 to 36 hours after the LH surge.

Impending ovulation can cause an uptick in vaginal discharge. This discharge is often clear and stretchy — it may even resemble raw egg whites. After ovulation, your discharge may decrease in volume and appear thicker or cloudier.

Ovulation may also cause:

  • light bleeding or spotting
  • breast tenderness
  • increased sexual drive
  • ovary pain characterized by discomfort or pain on one side of the abdomen, also called mittelschmerz

Not everyone experiences symptoms with ovulation, so these signs are considered secondary in tracking your fertility.

Your menstrual cycle resets the day that your menstrual flow begins. This is the start of the follicular phase, where the egg matures and is later released during ovulation, around day 14.

After ovulation comes the luteal phase. If pregnancy occurs during this phase, hormones will keep the lining from shedding with a menstrual period. Otherwise, a flow will start around day 28 of the cycle, beginning the next cycle.

In short: Ovulation generally occurs in the middle of the menstrual cycle.

Yes. Some people may ovulate more than once in a cycle.

One study from 2003 suggested that some may even have the potential to ovulate two or three times in a given menstrual cycle. Not only that, but in an interview with NewScientist, the lead researcher said that 10 percent of the study participants actually produced two eggs in one month.

Other people may release multiple eggs during one ovulation either naturally or as part of reproductive assistance. If both eggs are fertilized, this situation may result in fraternal multiples, like twins.

No. While the egg can only be fertilized in the 12 to 24 hours after it’s released, sperm can live in the reproductive tract under ideal conditions up to 5 days. So, if you have sex in the days leading up to ovulation or on the day of ovulation itself, you may become pregnant.

The six days leading up to and including ovulation make up what’s called the “fertile window.” Again, this is the period of time when sexual intercourse may lead to pregnancy.

The sperm may wait around for several days in the fallopian tubes after sex, ready to fertilize the egg once it’s finally released. Once the egg is in the fallopian tubes, it lives for around 24 hours before it can no longer be fertilized, thus ending the fertile window.

While the most accurate ways to confirm ovulation is with an ultrasound in the doctor’s office, or with hormonal blood tests, there are many ways to track ovulation at home.

  • Basal body temperature (BBT) charting. This involves taking your temperature with a basal thermometer each morning throughout your cycle to record its changes. Ovulation is confirmed after your temperature has stayed elevated from your baseline for three days.
  • Ovulation predictor kits (OPK). These are generally available over-the-counter (OTC) at your corner drugstore. They detect the presence of LH in your urine. Ovulation may happen within the next couple of days after the result line is as dark or darker than the control.
  • Fertility monitors. These are also available OTC. They’re a more expensive option, with some products coming in at around $100. They track two hormones — estrogen and LH — to help identify the six days of your fertile window.

It’s hard to say which method truly works better than another.

Charting your BBT may be impacted by a number of factors that influence your body temperature, like illness or alcohol use. In one study, charting only accurately confirmed ovulation in 17 of 77 cases. Keep in mind that in a year of “typical” use, 12 to 24 out of 100 people will get pregnant while using fertility awareness methods, like charting, to prevent pregnancy.

Fertility monitors, on the other hand, boast the potential to increase your chances of pregnancy with just one month of use. Still, these tools might not work well for everyone.

Talk with a doctor about your options if you:

  • are approaching menopause
  • have recently started having menstrual periods
  • have recently changed hormonal contraceptive methods
  • have recently given birth

You only need to have sex once during your fertile window to achieve pregnancy. Couples who are actively trying to conceive may up their chances by having sex every day or every other day during the fertile window.

The best time to get pregnant is in the two days leading up to ovulation and the day of ovulation itself.

If you want to prevent pregnancy, it’s important to use contraceptives during your fertile window. Although barrier methods like condoms are better than no protection at all, you may have a greater peace of mind when using a more effective method.

Your doctor or other healthcare provider can walk you through your options and help you find the best approach.

If the egg is fertilized, it begins the process of division into two cells, then four, and so on, until it becomes a 100-cell blastocyst. The blastocyst must successfully implant in the uterus for pregnancy to occur.

Once attached, the hormones estrogen and progesterone help thicken the uterine lining. These hormones also send signals to the brain to not shed the lining so that the embryo can continue its development into a fetus.

If the egg doesn’t become fertilized by sperm in a given menstrual cycle, the egg disintegrates. Hormones signal the body to shed the uterine lining in a menstrual period that lasts between two and seven days.

If you track ovulation from one month to the next, you may notice that you’re either not ovulating regularly or — in some cases — not ovulating at all. This is a reason to speak with a doctor.

Although things like stress or diet may impact the exact day of ovulation from month to month, there are also medical conditions, like polycystic ovary syndrome (PCOS) or amenorrhea, that may make ovulation irregular or stop completely.

These conditions may cause other symptoms related to hormonal imbalances, including excess facial or body hair, acne, and even infertility.

If you’re looking to get pregnant in the near future, consider making a preconception appointment with a doctor or other healthcare provider.

They can answer any questions you may have about ovulation and tracking, as well as advise you on how to time intercourse to increase your chances.

Your provider can also identify any conditions that may be causing irregular ovulation or other unusual symptoms.