Not sure how to rank these in order of merit, but I have had all of these experiences.
1. Pro chick let me go down on her only to tell me afterward that she was on her period. WTF? Did she hide a tampon and I didn't notice????? Why would any of this even happen? Very disconcerting. I called her agency to let them know this was not cool. (Consolation prize: No visible blood or evidence was noticed.)
2. SA chick puts up last minute resistance by saying she's on her period. I say, "No problem," spread a towel, and lift her sweet petiteness onto it. The towel was snowy white when we finished.
3. SA chick says she can't meet because she's on her period. I say I'm sure she can be creative. She swallows every drop.
4. SA regular chick waits until we're getting ready for bed to tell me she's on her period. She also swallows every drop.
5. New SA chick announces in the heat of the moment that she's on her period. I put her on a towel. She isn't bluffing. Bloody mess.
6. New SA chick fucks with total abandon, only to complain immediately afterward of not feeling well. Says her period might be starting and consults some bullshit app. Yes, there is some blood which embarrasses her. She asks for Advil and nearly falls in love with me because I keep some handy. I rub her back. Months later she still tells me no one ever cared for her so tenderly.
7. In bed with two new SA chicks. The less attractive one announces she's on her period. I notice the more attractive one has "wings" (some kind of period pad or something) poking out of her panties. I press on with the prettier one, never mentioning anything related to period, while her bff plays a supporting role (all the while complaining how horny she is). Eventually the prettier one cries out, "It's your pussy, Daddy!" In the end, no blood was seen.
8. This last one is not about period blood, it's about virgin blood. New SA chick, a virgin. Much of the evening seemed awkward. That turned out to be because it was her first time. She was very hard to get into. Plenty of blood. Messy sheets. Big, big tip for the housekeepers.