I'm only into this hobby a few months, and just a few visits with providers.  Mostly massages, only a couple special occasions went FS.
I was looking for a FS session and found one that had an incall pretty close to my place of employment. Had seen her reviews, and ads, thought I'd give her a try.
Set an appointment, she was running late. Anyways, had a pretty nice time, got the fs, then she said she'd be right back with something to clean me up with.   She comes back with some wet wipes, I start cleaning myself and the wipes are bloody. WTF?  She made a comment "I guess I'm done with appointments for today". Anyways, needless to say I used the shower and some 60 grit sandpaper to clean up. I won't be writing a review and don't want to out her, but I guess I just wanted to vent a bit.

This is all about Mother Nature and it doesn't follow an exact clock. By what you said seems she may have been just as surprised?? I think it may happen more then you may think so it really doesn't shock me that much. I do know of one gal that will work right through her little cycle and that does kinda creep me out... Wouldn't you just take the few days off?? I can understand the frustration and wanting to vent but we don't always need to know all the details just my 02 cents worth.. And really commend you on not bring her name into it..

Who hasn't started a period by having sex?? If if hasn't happened to you, it will.

Not like she could help it. She was probably embarrassed as hell

My question is...why would she hand you wipes to clean your self up with that have obviously been used?

I would not make a big deal about it.  Not every woman's cycle arrives on schedule, and sometimes it happens at unfortunate times.  Its part of being a woman.  I had it happen to me when I was with a provider once.  It increases your risk slightly.  If you used a condom and had no open sours, the risk is minimal.  Sounds like you cleaned up well, that reduces the chance of transmitting anything.