Since the relationship between menstrual periods and pregnancy can be confusing, many women assume they can’t get pregnant right after a period stops. However, depending upon your time of ovulation and the length of your period and menstrual cycle, you may in fact be able to get pregnant right after the end of your period.
Your menstrual cycle is measured from the first day of your menstrual period until the first day of the following period. Most menstrual cycles last about 28 days, but they can vary in length from 21 to 35 days in adult women, according to the U.S. Department of Health and Human Services.
The American Pregnancy Association states that the majority of women experience ovulation—the release of a mature egg from one of your ovaries—some time between day 11 and day 21 of the menstrual cycle. This egg is available for fertilization for approximately 12 to 24 hours following ovulation.
If the egg is not fertilized within 24 hours of ovulation, then it disintegrates along with the thickened lining of your uterus and leaves your body in the monthly discharge of tissue and blood known as your menstrual period. Typically lasting three to five days, your menstrual period could also be as short as two days or as long as seven days and still be normal.
Pregnancy occurs when a live sperm penetrates and fertilizes the egg waiting in your fallopian tube. According to the American Pregnancy Association, sperm can live inside your reproductive tract for three to five days.
You could get pregnant if you have sexual intercourse right after your period ends, if all conditions are right. For example, if you have a period that lasts seven days and your menstrual cycle lasts only 21 days, then you could ovulate as early as day 11 of your cycle; sperm placed in your reproductive tract on day eight of your cycle could easily fertilize the egg immediately following ovulation, thus resulting in pregnancy right after your period.