Fertile window

The fertile window is the span of days in a menstrual cycle when intercourse is most likely to result in pregnancy — typically the five days before ovulation plus the day of ovulation itself, reflecting sperm survival time and the short lifespan of the released egg. Timing intercourse within this window, often identified using cycle tracking, ovulation predictor kits or clinical monitoring, is a common first step recommended before or alongside fertility treatment.

Also known as: fertile days, ovulation window, best days to conceive

Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.