When you’re ovulating, one of your ovaries is releasing a mature egg into your fallopian tube, where it can potentially be fertilized by sperm. This typically happens once per menstrual cycle, around day 14 of a 28-day cycle, though the exact timing varies from person to person. Ovulation is the brief window when pregnancy is possible, and your body produces several noticeable signals before and during it.
What Happens Inside Your Body
Ovulation is triggered by a surge of luteinizing hormone (LH), a chemical signal sent from your brain to your ovaries. This surge kicks off a chain reaction: enzymes begin breaking down the outer wall of the follicle, which is the small fluid-filled sac in your ovary that’s been nurturing a developing egg. Over the hours that follow, layers of tissue in the follicle wall are dissolved by different waves of enzymes until the wall is thin enough for the egg to break through and enter the fallopian tube.
Once the egg is released, it survives for roughly 12 to 24 hours. Sperm, by contrast, can live inside the reproductive tract for 3 to 5 days. That mismatch is why your fertile window is actually several days long, not just the moment of ovulation itself. The days leading up to ovulation are often the most fertile, because sperm can already be waiting when the egg arrives.
How Your Hormones Shift
Your hormone levels change dramatically around ovulation. In the first half of your cycle (before the egg releases), progesterone stays very low, typically between 0.1 and 0.7 ng/mL. After ovulation, progesterone climbs significantly, reaching anywhere from 2 to 25 ng/mL. This rise is what prepares the lining of your uterus for a potential pregnancy.
Estrogen also plays a key role. It rises steadily in the days before ovulation, peaking just before the LH surge. That estrogen peak is what triggers LH to spike, which in turn triggers the egg’s release. After ovulation, estrogen dips before rising again more modestly in the second half of your cycle. These shifting hormones are responsible for most of the physical signs you might notice.
Signs You Can Actually Feel
Your body gives several clues that ovulation is happening or about to happen. The most reliable one you can observe at home is a change in cervical mucus. In the days leading up to ovulation, your discharge becomes wet, stretchy, and slippery, often described as resembling raw egg whites. This consistency helps sperm travel more easily. Earlier in your cycle, mucus tends to be thicker, stickier, or barely noticeable.
Some people also experience a one-sided pain in the lower abdomen right around ovulation. This is sometimes called mittelschmerz (German for “middle pain”). It occurs on whichever side the ovary is releasing the egg, and it can feel dull and achy like a mild cramp, or sharp and sudden. For most people it lasts a few minutes to a few hours, though it occasionally lingers for a day or two. Slight spotting or light vaginal bleeding can accompany it.
Other signs are subtler. Your basal body temperature (the lowest temperature your body reaches during rest) rises slightly after ovulation, typically by less than half a degree Fahrenheit. You won’t feel this change, but if you’ve been tracking your temperature each morning before getting out of bed, you’ll see it on a chart. The temperature stays elevated until your next period, confirming that ovulation occurred. The catch is that it only tells you after the fact, not in advance.
When Ovulation Happens in Your Cycle
The textbook answer is day 14 of a 28-day cycle, counting from the first day of your period. But a “normal” cycle length ranges from 21 to 35 days, which means ovulation day shifts accordingly. If your cycles are shorter, you likely ovulate earlier. If they’re longer, ovulation comes later. Even from month to month, the day can vary by several days in the same person. Stress, travel, illness, and sleep changes can all shift timing.
This variability is why calendar-based predictions alone aren’t very reliable. Paying attention to cervical mucus changes or using ovulation predictor kits gives you a more accurate picture of what’s happening in a given cycle.
How to Track Ovulation
Ovulation predictor kits (OPKs) are urine tests you can buy at any pharmacy. They detect the LH surge that happens about 1 to 1.5 days before ovulation. The FDA reports these kits detect LH reliably about 9 times out of 10 when used correctly. A positive result means ovulation is likely within the next day or two, making it useful for timing intercourse if you’re trying to conceive.
Combining methods improves accuracy. Tracking cervical mucus tells you when fertility is rising (the mucus becomes slippery and stretchy), while an OPK can confirm the LH surge is underway. Basal body temperature tracking confirms ovulation happened after the fact, which is helpful for understanding your cycle patterns over several months even if it doesn’t predict ovulation in real time.
When Ovulation Doesn’t Happen
Not every cycle includes ovulation. Anovulation, or the absence of egg release, is more common than many people realize. The most frequent cause is polycystic ovary syndrome (PCOS), a hormonal condition rooted in insulin resistance. When the body is resistant to insulin, the ovary responds by not growing follicles properly and not releasing eggs on a regular schedule. PCOS is typically diagnosed when someone has at least two of three features: irregular cycles (fewer than eight periods a year or cycles longer than 35 days), polycystic-appearing ovaries on ultrasound, and signs of elevated testosterone such as acne or excess hair growth.
Thyroid problems can also disrupt ovulation. Both an overactive and underactive thyroid interfere with the hormonal signals that regulate your cycle. Elevated prolactin, a hormone produced in the brain, is another potential cause. Obesity and diabetes contribute through the same insulin resistance pathway involved in PCOS. Even significant stress or sudden weight changes can temporarily shut down ovulation by disrupting the hormonal cascade that starts in the brain.
If your cycles are consistently irregular, very long, or absent, it may mean you’re not ovulating regularly. Irregular cycles don’t always indicate a serious problem, but they’re worth investigating if you’re trying to get pregnant or if the pattern represents a change from what’s been normal for you.