So may girls no going bareback

I have noticed a bunch of girls are offering BBFS both top and bottom. I was with a few and they asked me if they can fuck me BB and a few when I didn't cum fast they asked if I wanted to go BB. One girl even when we were in the middle with her on top took the condom off without asking, I found out when she came and cum was all in my ass and cheeks, was not happy BTW.
Are they doing it because they don't care, or on PreP? I was with a girl and she said not to worry she was on PreP another said she was undetectable, which I ran from. I have even see girl advertising on back page for Raw
Attachment 1040273