The fertile window usually includes several days before ovulation and a short time after. Body signs can help, but they do not guarantee exact ovulation timing.
The fertile window usually includes several days before ovulation and a short time after. Body signs can help, but they do not guarantee exact ovulation timing.
Because sperm can survive about 3–5 days while an egg lives only 12–24 hours after release, the "fertile window" spans roughly the 5 days before ovulation plus the day itself — about six days. Conception is most likely in the two days before ovulation and on the day of ovulation.
Estimating from the "midpoint" is unreliable when cycles vary. Combining cervical-mucus checks with LH strips beats the calendar method alone. Logging BBT and test results over a few cycles gradually reveals your own pattern.
Consider a fertility evaluation after one year of trying under 35, or six months at 35 and over. Persistently disordered ovulation signs, very infrequent periods or absent periods also warrant an early check.
The fertile window is about six days — the five days before ovulation plus ovulation day — with the highest chance in the two days before and the day of ovulation.
A temperature rise shows ovulation has already occurred, so it is retrospective. To predict ahead, use LH test strips or track cervical mucus.
The calendar method alone is unreliable; combine cervical-mucus observation with LH strips and track several cycles to learn your pattern.
Medical disclaimer: This guide is for general education and pregnancy date planning only and does not replace professional medical advice, diagnosis or treatment. For your individual situation, consult your doctor or midwife.
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Written and checked by the Pregnancy Tools editorial team · Last reviewed 2026-06-24 · About a 2-minute read · See About us