I'm 19 years old and about 80% of the time after I come, blood comes out. It's a deeper red color. I've had a boyfriend for about 2 years now but we've never had sex and he's never broken my hymen (I'm afraid to have sex so he's being patient with me). I do get a depo shot every three months, and I never bled until after I started getting my depo shot which may have something to do with it. Also, because of the shot, I don't get my period anymore.
I don't think it has to do with my vagina being scratched on the inside, and there's no possibility that I have an STD because I've only been with my one and only boyfriend, and he hasn't had sexual partners before either.