with a medical back ground the female anatomy is slightly different in most females. all females should pee after having sex to help prevent getting a bladder infection. You can have some bleeding with vagina or annul sex. You should talk to her doctor with any concerns if you are having pain or bleeding with sexual intrecose. I will say that over 50% of females have your same concerns with most of them this is normal, however your doctor need to run some test. Some of your concern cause be very back (live altering). Talk with your doctor. most providers have come across your concerns with bleeding and/or pain.
I have a similar problem. I'm single so I often masturbate to various things. Typically videos. And every now and again I will complete my orgasm and I will immediately feel my arse open and release a small wallop of, what I first thought was poop. I knew the pressure sometimes triggered poop. The first time I was in bed and freaked out because it was blood. Since then I've always been on the toilet masturbating solely for the safety sake. I know it isn't because of a UTI or yeast infection. I've had both before and this have never happened during that. I'm highly irregular with my period, So I didn't know if it was the uterine lining trying to find a new escape (this theory was stupid and irrelevant once I became of sound mind and body). But you are not alone. I'm trying to figure it out before I go to see anyone.