Guest... you've got to be kidding?! Please say the machete incident didn't happen!!
Sex during menstruation is great for cramps and wonderful for the mood... but I always stay away from it during the last day or two of my period. Don't mean to be gross, but for me it can disturb the formation and placement of the "plug" that separates the vagina from the rest of the female paraphenalia after the period. I hate periods, so adding a day or two more to my cycle just ain't worth it. Or maybe the guy this happened with (several times!) is just too big... ;-)
And no, no way would I let any guy do anything oral during my period.