I don’t know how you do it, but personally I rarely engage in bloodsport in the middle of my masturbatory sessions. Mixing business and pleasure is notoriously bad form, old boy.
I’ve never understood what issue most guys have with menstruation. I presume it to be some sort of irrational inculcated aversion. Personally, I enjoy the consequence-free opportunity to come in my lady of choice. And, usually, so does she.