Your body gives several detectable signals before and during ovulation, and learning to read them can help you pinpoint your most fertile days each cycle. The most reliable signs include changes in cervical mucus, a slight rise in resting body temperature, and a positive result on an ovulation predictor kit. Some people notice only one of these, while others pick up on several at once.
Cervical Mucus Changes Throughout Your Cycle
Tracking your cervical mucus is one of the simplest ways to gauge where you are in your cycle, and it costs nothing. The pattern follows a predictable progression driven by rising estrogen levels as your body prepares to release an egg.
In the days right after your period, discharge is typically dry or tacky, white or slightly yellow, almost paste-like. Over the next several days it becomes creamy, similar to yogurt in consistency, and looks cloudy or white. Then, in the days leading up to ovulation (roughly days 10 through 14 of a textbook 28-day cycle), mucus becomes wet, stretchy, slippery, and clear. The classic description is that it looks and feels like raw egg whites. If you can stretch it between your fingers without it breaking, you’re likely in your most fertile window.
After ovulation, mucus dries up quickly, returning to thick and sticky until your next period. Not everyone follows this timeline exactly, so it helps to track your own pattern for a few cycles to learn what’s normal for you.
Basal Body Temperature
Your resting body temperature shifts slightly after you ovulate due to a rise in progesterone. The increase is small, typically less than half a degree Fahrenheit (about 0.2 to 0.5°C), so you need a thermometer sensitive enough to detect it. Take your temperature first thing in the morning before getting out of bed, ideally at the same time each day.
The key detail: the temperature shift tells you ovulation already happened, not that it’s about to. That makes it more useful for confirming ovulation after the fact than for timing intercourse in real time. Over several cycles, though, you’ll start to see a pattern that helps you predict when the rise is coming. Before ovulation, your baseline sits lower. After ovulation, it stays elevated for roughly 10 to 16 days until your period starts (or stays elevated if you’ve conceived).
Ovulation Predictor Kits
Ovulation predictor kits (OPKs) detect a hormone called LH in your urine. LH surges about 24 to 48 hours before the egg is released, so a positive test gives you a heads-up that ovulation is approaching. The egg itself is released roughly 8 to 20 hours after LH peaks.
These tests are quite accurate. A 2024 study comparing five popular brands found that all detected the LH surge with over 91% accuracy when compared to blood tests. Standard kits use a sensitivity threshold of 25 mIU/mL, which has been shown to give the best balance between catching real surges and avoiding false positives.
To use one, you typically start testing a few days before you expect to ovulate. For a 28-day cycle, that means starting around day 10 or 11. Test with afternoon or early evening urine rather than first morning urine for the most reliable LH reading. Once you get a positive result, your two most fertile days are that day and the following day.
Ovulation Pain
Some people feel a twinge or ache on one side of their lower abdomen around the time they ovulate. This is called mittelschmerz, and it can range from a dull cramp to a sharp, sudden pang. It usually lasts a few minutes to a few hours, though it occasionally lingers for a day or two. The side may alternate from month to month depending on which ovary releases an egg. Some people feel this every cycle, others only occasionally, and many never notice it at all. It’s a helpful secondary clue if you feel it, but not something to rely on as your only signal.
Other Subtle Signs
Your cervix itself changes position and texture during your cycle. Around ovulation, it tends to sit higher, feel softer, and open slightly. Earlier and later in the cycle, it sits lower, feels firmer, and stays more closed. You can check this by gently inserting a clean finger, though it takes practice to notice the differences.
Some people also notice increased sex drive, mild breast tenderness, or light spotting around ovulation. These signs vary widely from person to person and cycle to cycle, so they work best as supporting evidence alongside more reliable indicators like mucus changes or OPK results.
You may have seen saliva-based ovulation tests that look for a “ferning” pattern under a small microscope. Rising estrogen can cause dried saliva to crystallize into fern-shaped structures. The FDA notes these tests are not particularly reliable: not all people fern, ferning doesn’t always align with the fertile window, and results can be thrown off by eating, drinking, smoking, or brushing your teeth. They’re an interesting curiosity but shouldn’t be your primary tracking method.
Your Fertile Window Is Wider Than One Day
The egg survives only about 12 to 24 hours after release, but sperm can live for 3 to 5 days inside the reproductive tract. This means your fertile window stretches to roughly six days: the five days before ovulation plus ovulation day itself. The highest chance of conception comes about two days before ovulation, when the probability sits around 26%. By the day after ovulation, it drops to roughly 1%.
This is why methods that predict ovulation in advance, like cervical mucus tracking and OPKs, tend to be more useful for timing than basal temperature, which only confirms ovulation after the fact. Using two or three methods together gives you the clearest picture.
When Ovulation Doesn’t Happen
It’s possible to have what looks like a regular period without actually ovulating. This is called an anovulatory cycle, and it’s more common than many people realize. The bleeding that occurs can look like a normal period, making it easy to assume everything is on track. Anovulation is most often linked to irregular or missing periods, but it can occasionally happen to someone with an otherwise regular cycle.
If you’ve been tracking your signs and notice you never get the egg-white mucus, never see a temperature shift, or consistently get negative OPK results, those are clues that ovulation may not be occurring. Stress, significant weight changes, thyroid issues, and polycystic ovary syndrome are among the most common causes. A blood test for progesterone, typically drawn about a week after expected ovulation, can confirm whether you actually released an egg that cycle.