If having sex at that time of the month has you or your mate seeing red, then you might hold off in favor of those other three weeks. Believe it or not, there are a few benefits of having sex on your period. A survey done by MensHealth.com found that women, not men, were usually the ones to put the brakes on getting busy during Aunt Flo's visit. More than 75 percent of guys said they would love to have sex with their serious girlfriends or wives while they're on their period.  Women cite the "yuck" or "mess" factor as a major reason for their hesitation, but there are several steps that prevent it. A dark towel on the bed can minimize sheet stains, and the position you're in can help, too. Fight gravity by lifting your legs and keeping hips up, or allow him to enter from behind.