My ex and I were in a long distance relationship; sometime we got to see each other once a month, sometimes we wouldn't see each other for 3 months. Before we got together I was a "hell no, no sex on the rag" gal; but, I changed my mind. When he'd visit all the way from 'Frisco or NY or whatever state he was currently living for work, I had to go with the flow (ba-dump-bump) if the tide was red and Aunt Flo was visiting, because I had to keep in mind that sometimes it would be a while before we could give it a go again.
We had a lot of shower sex. That I didn't mind so much. In bed sex used to freak me out, though; my flow isn't light and we could easily kill a lot of towels and the mattress if we went at it for a long time.
Now that I'm not in that relationship any longer, I'm not really into period sex anymore. Eh. I can wait, lol.