Cycle × body · 5 min
Ovulation pain: where it comes from and how to tell it apart
Mittelschmerz — German for "middle pain" — is ovulation pain felt by an estimated 20–40% of menstruating people. Not in every cycle, not always the same intensity. It's physiological.
What it typically looks like
- Appears around day 13–15 of a 28-day cycle, near ovulation.
- One side of the lower abdomen — the side releasing the egg that cycle. The side can switch between cycles.
- Lasts from a few minutes to about 48 hours.
- Character: dull, throbbing, sometimes sharp or pulling.
- May come with EWCM mucus, light mid-cycle spotting, bloating.
What causes it
The mechanism isn't fully clear. Most likely several things at once: stretching of the ovarian follicle just before rupture, a small leak of fluid and blood into the abdomen irritating the peritoneum, and contractions of the fallopian tube catching the egg. Ovulation pain is not a sign of disease.
Telling it apart from other pain
- From menstrual cramps — this is mid-cycle, not during bleeding, usually one-sided.
- From appendicitis — appendix pain builds, comes with fever and rebound tenderness; ovulation pain settles within a day.
- From ovarian cysts — cysts usually hurt longer and independently of cycle phase.
- From endometriosis — cyclical, but often intense, growing each cycle, paired with painful periods.
When to check with a doctor
- Pain lasts longer than 48 hours or is very intense.
- Comes with fever, vomiting, bleeding outside the period.
- Disrupts daily functioning every time.
- Appears only after age 35–40 in cycles where it never used to — happens in perimenopause but worth ruling out cysts.
What this means in practice
Ovulation pain is one of the most reliable signs that ovulation actually happened in a given cycle — especially paired with EWCM. Useful information whether you're trying to conceive or the opposite. In perimenopause, pain + EWCM together can be the only signal that ovulation still happens despite irregular cycles.