Ovulation Happens 14 Days After a Period
Couples who are either trying to conceive -- or trying to avoid a pregnancy -- by using the "rhythm method" will often simply abide by this basic rule to increase or decrease their odds of having a child. But, according to a study done by the National Institute of Environmental Health Sciences, only about 30 percent of women are fertile during days 10 to 17 of their menstrual cycles. While 14 days after a period might be good as a general guide, it isn't the most accurate way to predict fertility.
For the most accurate prediction of what is known as the "fertile window," your best bet is to use a luteinizing hormone (LH) predictor kit as previously described.