Mittelschmerz: a one-sided lower-abdominal twinge, cramp, or dull ache arriving mid-cycle (about two weeks before the period), lasting minutes to a day or two, sometimes with light spotting - the follicle stretching or rupturing as it releases the egg.
Common, harmless, and useful as a fertility signal: it marks the window closing. The separation lines: severe pain, duration past a couple of days, fever, vomiting, fainting, heavy bleeding, or wrong timing in the cycle - and sudden severe one-sided pain is same-day evaluation, not watch-and-wait.
What to do
Common questions
What does ovulation pain feel like?
Ovulation pain has a name - mittelschmerz, German for "middle pain" - and a recognizable signature: a twinge, cramp, or dull ache low in the abdomen on ONE side (the side that released the egg that month - it can alternate), arriving mid-cycle, roughly two weeks before the period is due, lasting from minutes to a day or two, sometimes with light spotting or discharge. It is common and harmless - probably the follicle stretching or rupturing as it releases the egg. The useful part: it is a free fertility signal - for people trying to conceive, it marks the window closing, not opening (the egg lives about a day). The lines that separate normal mittelschmerz from lookalikes: pain that is severe, lasts beyond a couple of days, comes with fever, vomiting, fainting, or heavy bleeding, or arrives at the wrong cycle time - those point to ovarian cysts, torsion, endometriosis, or appendicitis, and sudden severe one-sided pain is a same-day evaluation, not a watch-and-wait. Pymander, a free AI doctor available 24/7 by text, can help you time and place the pain against your cycle.