What is ovulation pain (mittelschmerz)?

Bottom lineOvulation pain (mittelschmerz) is a usually harmless one-sided lower-abdomen ache or twinge around ovulation, on the side releasing an egg, lasting minutes to a couple of days; it may come from the follicle stretching the ovary or fluid released at ovulation. It's a supporting clue for tracking but not reliable alone; see a doctor for severe pain, pain lasting over 2 to 3 days, or pain with fever, nausea, or heavy bleeding.

Ovulation pain, called mittelschmerz (German for "middle pain"), is a one-sided ache or twinge in the lower abdomen around the time of ovulation. It's common and usually harmless.

What it feels like

• A dull ache or sharp twinge on one side of the lower abdomen
• On the side where the ovary is releasing an egg (can switch sides cycle to cycle)
• Lasts anywhere from a few minutes to a couple of days
• Mild, not severe

Why it happens

The exact cause isn't certain, but it may relate to the follicle stretching the ovary before release, or a small amount of fluid or blood released at ovulation irritating the area.

Is it useful for tracking?

It can be a supporting clue that you're ovulating, but because it doesn't happen for everyone and isn't precisely timed, it shouldn't be your only signal. Pair it with cervical mucus or OPKs.

When to see a doctor

• Pain that's severe or lasts more than 2 to 3 days
• Pain with fever, nausea, or vomiting
• Pain during sex or with heavy bleeding
• Sudden, intense one-sided pain (seek urgent care to rule out other causes)

Severe or persistent pelvic pain can point to conditions like endometriosis or ovarian cysts.

See ovulation symptoms and track it in Femora.

Femora lets you log mid-cycle pain alongside other ovulation signs to confirm the timing.