I'm 20 years old and starting last week I had sex with my girlfriend and when i ejaculated it was almost all blood, I masturbated a few days after and it was normal, then today we had sex again and there was a lot less blood but still maybe 50% blood. There is no pain at all when peeing or having sex, and no blood when I pee, usually there is some the first time I pee after sex but that's because the blood clots inside every time after that there isn't a trace of blood. What could this be?
You need to see your own doctor, go to a sexual health service - or if you are in the uk there are also GUM Clinics you can go to - ir may be wise to phone one first to see if you can get an in-person appointment.
You need to do this straight away - do not leave this condition any longer !