After having sex, fertilization (when sperm meets the egg) can occur anywhere from minutes up to 12 hours after ejaculation if ovulation is happening. Sperm can survive inside the female reproductive tract for up to 5 days, meaning conception can happen even if sex occurs several days before ovulation. Once fertilization occurs, the fertilized egg travels to the uterus for implantation, which generally takes about 6 to 12 days after conception (or 5 to 15 days after sex). A woman is considered pregnant only after the embryo implants in the uterine lining. In summary:
- Sperm can reach the egg in as little as 15 minutes to a few hours.
- Fertilization can happen up to 5 days after sex due to sperm longevity.
- Implantation, marking the start of pregnancy, usually occurs 6 to 12 days post-fertilization.
- Therefore, pregnancy typically begins about 6 to 12 days after sex, depending on timing relative to ovulation.
If trying to conceive, many couples have about a 20-30% chance to get pregnant each month during the fertile window.
