Sex during your period? Good or bad?

Let's talk about sex during our periods. After doing some research within my group of girlfriends, it seems like we all do enjoy a little fun time while our menstration. Now I wonder if others enjoy it as well? Has anyone allowed their sex partner to ejaculate in them while on their periods? If so where you scare of pregnancy? I have found it that most men truly don't seem to care about our time of the month as long as we feel sexy and confident. Any opinions?