It’s a question many ask. Pregnancy happens when a sperm fertilizes an egg. Ovulation is when an egg is released from the ovary — usually about halfway through the cycle — but this timing can vary. The egg lives for about 24 hours, while sperm can survive inside the uterus and fallopian tubes for up to five days.

This means you can become pregnant from sex that happens in the days leading up to ovulation, not just on the exact day. The “fertile window” is roughly six days long: the five days before ovulation and the day it occurs. Stress, illness, and sleep changes can shift ovulation, so it’s not a perfect science.

Alma’s tip:

If you’re trying to conceive, think in cycles, not single days. If you want to avoid pregnancy, use contraception consistently, because your body doesn’t always follow a calendar. The more you understand your rhythm, the easier it becomes to feel at peace with your body’s timing.