There isn't any physiological reason why a couple shouldn't have sex during a woman's period.
All aspects of her sexual response are the same. In fact, couples can use a vibrator or have oral sex, if they choose.
What usually stops many a couple from having sex during her period is the 'ick' factor. Yet some women find the experience quite erotic as she already has the 'full' feeling in her pelvic area.
The best way to navigate the "should we have sex during your period" situation is let the woman be the guide as to what is going to happen over that three to seven days.
A word of caution: although it is very rare, there is a slim chance a gal can get pregnant during her period. As well, be cautious and protect yourself from blood-borne pathogens such as HIV and Hepatitis. Condoms and dental dams are always the best way to protect you and your partner.
Great Sex Tip:
If you feel a bit uncomfortable about the potential mess but at the same time are horny, a good idea is to have sex in the shower. Otherwise, an old towel laid out will do the trick nicely.
Originally posted: http://trinaread.com/articles/can-i-have-sex-during-my-period