The "safe days" before and after a period, when the chance of pregnancy is lower, generally include about 7 days before the period starts and 7 days after the first day of menstruation. This method, sometimes called the "7 days before, 7 days after" rule, assumes a regular menstrual cycle and helps to avoid intercourse during the fertile window around ovulation to reduce pregnancy risk. However, it is not 100% reliable, especially for women with irregular cycles, because sperm can live up to 5 days in the uterus and ovulation timing can vary.
More specifically:
- The 7 days after the period begins are often considered relatively safe because ovulation usually occurs about 14 days before the next period.
- The 7 days before the next period also tend to be safer, as fertility declines after ovulation.
- The "fertile window" typically starts around day 8 of a 26- to 32-day cycle through about day 19, with the highest chance of conception in the 4-5 days leading up to and including ovulation.
Importantly, pregnancy can still occur with intercourse shortly after the period ends or even during the period if cycles are short or irregular. Using contraception is the most reliable way to prevent pregnancy. In summary: About 7 days before and 7 days after the period start are commonly considered relatively safe days, but this varies by individual cycle and is not a guaranteed safe period without contraception.
