II Misconception: "The best way to conceive is not to have sex for a week and then give it one good shot when the woman's temperature goes up."
Reality: Having sex early and often—about every other day from about four days before a woman thinks she's going to ovulate until a day or so after—makes conception most likely. If you wait for a week, Dr. Copperman explains, "First of all, you're going to have a whole bunch of old sperm there, rather than fresh sperm if the man had ejaculated a day or two before. Secondly, part of the time, you're going to miss ovulation. Ideally, you really want the sperm there before the egg is released."
Sperm can survive for several days, while the egg loses viability quite rapidly, some estimate within 24 hours. While day 14 is the standard, the time of ovulation varies from woman to woman and sometimes from cycle to cycle. Charting temperature, noting cervical mucus changes, or using ovulation-predictor kits will help a woman become more familiar with her cycle and determine the best time to conceive.