Generally I try to avoid sex during my period because of the sensitivity. My cervix sits pretty low when I'm on it so I'm sure that contributes greatly to the discomfort (it doesn't really like to be prodded harshly, period or not). Doesn't feel so sensitive if we take time with foreplay and being gentle.

Yes! I have endometriosis, so that's a big contributing factor as to why I feel so much pain when I mix my period with sex. LOL. However, for about 4 years of our time together (we've been together for 6), sex during my period was NOT an option. It was so painful, but I had surgery for the endo. over a year ago, so now I'm better and only have "minimal growth," so I can have sex during the end of my period without pain. I also take medication that stops my flow, but since my menstrual cycle "symptoms" are so extreme, I still feel them quite a bit. Sex is not preferrable during my time of the month since it is painful during certain days still, but I do really enjoy it A LOT only days before my period begins.