Sperm can live in the female reproductive tract for up to three days after intercourse, so having sex every day, or even on ovulation day, is not necessary. What is critical is knowing when you are fertile. According to data from the AIA, 20 percent of couples seeking infertility treatment are not timing intercourse correctly.
A woman is fertile for a period of six days, the five days leading up to ovulation (when the egg is released from the ovary) and the day of ovulation. A study by the National Institute of Environmental Sciences found, much to the researchers' surprise, that a woman 's capacity to conceive seems to end on ovulation day. So if women charting their basal body temperature are waiting for their temperature to go up to have intercourse, they're too late, warns Melissa Holmes, MD, associate professor of obstetrics and gynecology at the Medical University of South Carolina in Charleston. She recommends using ovulation kits because they let you know when you're about to ovulate. Having sex on the two days prior to ovulation offers the greatest chance of conception.