When Am I Most Fertile?

Whether you're trying to conceive or avoid pregnancy, knowing your fertile window matters. The window is shorter than most people realize — and it's not exactly the middle of your cycle for everyone.

The fertile window

You're most fertile in the 6 days leading up to and including ovulation. Sperm can survive in the reproductive tract for up to 5 days; the egg lives 12–24 hours. Sex in this window has the highest chance of leading to pregnancy.

Predicting ovulation

If you have a 28-day cycle, ovulation is typically around day 14. But cycles vary. Tracking apps use your past cycle data to estimate. Ovulation predictor kits (LH strips) detect the surge that triggers ovulation, usually 12–36 hours in advance.

Body signs

Cervical mucus becomes clear, stretchy, and slippery (like raw egg white) around ovulation. Basal body temperature drops slightly just before ovulation, then rises by 0.2–0.5°C and stays elevated. Some experience a mild twinge on one side (mittelschmerz).

Why timing matters less than people think

Once you've had sex in the fertile window, additional days don't dramatically improve odds. Stress about exact timing can be counterproductive. Aim for sex every 1–2 days in the fertile window if trying to conceive.