Ovulating means one of your ovaries is releasing an egg that can potentially be fertilized. It happens once per menstrual cycle, typically around the midpoint, and it’s the only time during your cycle when pregnancy is possible. The entire process is driven by a precise sequence of hormonal signals that build over days before the egg is actually released.
What Happens Inside Your Body
Each ovary contains thousands of follicles, which are tiny fluid-filled sacs that each hold an immature egg. During the first half of your menstrual cycle, hormones from your pituitary gland prompt several follicles to start growing. Usually, one follicle outpaces the rest and becomes the “dominant” follicle. As it grows, the cells surrounding the egg multiply, and fluid accumulates inside the sac.
The growing follicle produces rising levels of estrogen. Once estrogen reaches a critical threshold and stays elevated for roughly 50 hours, it triggers a surge of luteinizing hormone (LH) from the pituitary gland. This LH surge is the direct trigger for ovulation. It begins about 34 to 36 hours before the egg is released and causes the follicle wall to thin, break down, and eventually rupture. Ovulation itself, the moment the egg exits the follicle at the surface of the ovary, occurs about 10 to 12 hours after LH peaks.
The released egg is swept into the nearest fallopian tube, where it can meet sperm. If no fertilization occurs, the egg breaks down within 24 hours.
Signs You May Be Ovulating
Many people ovulate without noticing anything at all. But your body does produce several detectable signals around ovulation, some subtle and some obvious.
Cervical mucus changes. In the days leading up to ovulation, vaginal discharge shifts from sticky or creamy to wet, slippery, and stretchy, often compared to raw egg whites. This change makes it physically easier for sperm to travel through the cervix. You’ll typically notice this egg-white consistency around days 10 to 14 of a 28-day cycle.
Ovulation pain. Over 40% of people with ovaries experience a sensation called mittelschmerz, a German word for “middle pain.” It’s a one-sided lower abdominal ache (more commonly on the right side) that can range from barely noticeable to sharp and intense. It happens around the time the follicle ruptures and usually resolves within hours, though it can occasionally last a day or two.
Basal body temperature shift. After ovulation, your resting body temperature rises slightly, typically less than half a degree Fahrenheit (as little as 0.4°F or as much as 1°F). This rise is caused by progesterone, which the ruptured follicle starts producing after releasing the egg. The temperature stays elevated until your next period. Because the shift happens after ovulation, it confirms that you’ve already ovulated rather than predicting it in advance.
The Fertile Window
A released egg survives less than 24 hours. Sperm, on the other hand, can live inside the uterus and fallopian tubes for 3 to 5 days. This mismatch is what creates the “fertile window,” a span of roughly six days ending the day after ovulation. The highest chance of conception comes from sex in the two days before ovulation, when sperm are already waiting in the fallopian tubes by the time the egg arrives.
If you’re trying to conceive, the goal is to identify when ovulation is approaching rather than confirming it after the fact. If you’re trying to avoid pregnancy, knowing this window helps you understand when the risk is highest, though tracking alone is less reliable than other contraceptive methods.
How to Track Ovulation
Over-the-counter ovulation predictor kits (OPKs) detect the LH surge in your urine. Since the surge starts 34 to 36 hours before ovulation, a positive result gives you a useful heads-up. Sensitivity varies by brand, with most popular test strips correctly detecting the surge around 69% to 77% of the time. A negative result doesn’t always mean you’re not about to ovulate; the surge can be brief enough to miss if you only test once a day.
Tracking basal body temperature requires taking your temperature first thing every morning before getting out of bed. Over a few cycles, you’ll see a pattern: lower temperatures before ovulation, then a sustained rise afterward. This method is better for understanding your cycle over time than for pinpointing the fertile window in real time, since the temperature increase only shows up after ovulation has already happened.
Cervical mucus monitoring costs nothing and gives you a real-time signal. When your discharge becomes clear, wet, and stretchy, ovulation is likely approaching within a day or two. Combining mucus tracking with OPKs gives you the most complete picture without needing a doctor’s visit.
When Ovulation Doesn’t Happen
Not every cycle produces an egg. Anovulation, the absence of ovulation, is most commonly caused by hormonal imbalances. Polycystic ovary syndrome (PCOS) is the leading cause in people of reproductive age. In PCOS, elevated androgen levels prevent follicles from maturing fully, so they stall at a small size instead of growing large enough to rupture and release an egg.
Other common causes include very low body weight or BMI, excessive intense exercise, and pituitary gland dysfunction. These conditions reduce the production of LH and the follicle-stimulating hormone (FSH) needed to drive follicle development. Anovulation is also normal and expected during certain life stages: the first few years after periods begin, during breastfeeding, and as you approach menopause.
The most obvious sign of anovulation is irregular or absent periods. If your cycles are consistently shorter than 21 days, longer than 35 days, or unpredictable in length, ovulation may not be occurring regularly. A healthcare provider can confirm this with blood tests measuring hormone levels at specific points in your cycle.