Lo básico del ciclo

Ovulation and its signs

Revisado: 4 de octubre de 2026

Solo en inglés por ahora

Ovulation is when an ovary releases an egg, usually 10 to 16 days before your next period. Here is when it happens, the signs some people notice, and what a calendar cannot tell you.

What happens at ovulation

Ovulation is the moment one of your ovaries lets go of an egg. In the days before, the egg ripens inside a small sac called a follicle. A sudden rise in luteinising hormone (LH) then makes the follicle let the egg go. The egg moves into the nearby fallopian tube, where tiny hairs help carry it towards the womb (uterus). If sperm reach the egg in the tube, it can be fertilised there.

When it happens

Ovulation usually happens about 10 to 16 days before your next period starts. In a 28-day cycle, that is around day 14. In a 35-day cycle, it would be closer to day 21. The number of days before ovulation can differ between people, and from month to month in the same person. This is why ovulation does not fall on the same cycle day every time, and why a calendar can only estimate it.

Signs you might notice

Signs vary from person to person. In the days before ovulation, cervical mucus often gets wetter, clearer and stretchy, a bit like raw egg white. Some people feel ovulation pain. This is a dull ache or sharp twinges on one side of the lower tummy, lasting from a few minutes to 1 or 2 days. A little spotting or extra discharge can happen too. Your body temperature at rest rises slightly just after ovulation, so by the time you see the rise, your most fertile days have usually passed.

Your fertile window

Once it is released, the egg lives for only about 12 to 24 hours. Sperm, though, can survive in the body for up to 7 days after sex. So pregnancy is possible from sex in the days before ovulation as well as on the day itself. These days together are called the fertile window. Because ovulation can come earlier than expected, pregnancy is also possible soon after a period, although it is less likely.

What a calendar cannot tell you

The ovulation phase and fertile window shown in Ciclo are estimates, not a test, and Ciclo is not contraception. A calendar cannot confirm that you ovulated, or exactly when. Home ovulation tests look for the LH surge, and a doctor can check your hormone levels with a blood test if needed. If you want to avoid pregnancy, ask a doctor, nurse or sexual-health clinic about reliable methods.

When to get checked

See a doctor or nurse if pain in the middle of your cycle does not ease with painkillers or keeps coming back. Pain like this sometimes has another cause, such as endometriosis, an ovarian cyst or an infection like chlamydia. Get help the same day if the pain is severe and painkillers have not helped. If you might be pregnant, even without a positive test, contact a doctor or nurse the same day if you have pain low down on one side of your tummy or any bleeding. Get emergency help for sudden, severe tummy pain, pain in the tip of your shoulder, heavy bleeding, or feeling very dizzy or faint. These can be signs of a pregnancy growing outside the womb (ectopic pregnancy).

This is general information. Estimated ovulation dates are not a test and not contraception. For sudden or severe pain, get medical help.