Heavy Bleeding; Really Bad Cramps; Birth Control; After Sex

Alright... I'm 15 years old and I just had sex with my boyfriend(first time for both of us) on June 6. I know I'm super young and I really don't want any critisizm, seeing as I'm getting a lot of it from my parents right now. We had sex four times, lasting usually around two hours, which is weird because neither of us ever orgasmed and the last time we had sex, I believe it was the 12th of June. I'm on birth control, not exactly sure what kind, but I don't even take the sugar pills so I don't get any type of period because I'm severely annemic and I have a history of bad periods and endometriosis and the periods are so bad that I get scared about the next time I get my monthly. After we had sex for the first time I was bleeding lightly and it had been that way for a little while, and then it turned into a really light blood, almost orange. Recently it's gotten so bad, though that I have cramps that have me bending over in tears and no pain medicine helps. The cramps are almost like contractions and they come and go and I just started bleeding really heavy, clots and all. I have no idea what it is. I'm going in for a pelvic exam and a pap smear on the 16th, I think. People keep telling me that it could be stress or an infection. I don't know... I guess I'm just asking if anyone knows what the hell this is ? Or if anyone's gotten it before ? I'd really appreciate if someone could help... Thank you so much.