need some help

alright so first i didn't know what category this would go into but here i go. so about 6 months ago i start feeling abdominal pains when i would have sex, and sometimes when i went to the bathroom. so the pains didnt stop, and i started to slightly bleed when i was having sex *mind you i was extremely wet, so the chance of it just being because i was dry is highly unlikely* sometimes the pains would feel as if there was a lot of water backed up in my stomach, and sometimes it felt like a knife stabbing me. so this recent june i had a physical and i let my doctor know about this. she told me that if it continued to hurt like this that i should go get it checked out again. so just this week i had sex, mind you the pains dont stop, after we were done my boyfriend pulled out and there was an excessive amount of blood on the condom and also on me and slowly down my leg. now i know you might think your period? well no, im on birth control and i still had a week left. so it stopped bleeding after 5 mins, i went to the bathroom and when i went to the bathroom there looked to be little blood clots, not bigger than the seeds on strawberrys. we kinda just let it go and said whatever. well 7 hours after that we tried again, well same thing happened, same with the blood clots. so im pretty experienced w have sexual activities, and im not stupid enough to not wear condoms or to not pull out. but im not sure what the hell is going on. I've made a appointment for the doctors but its 2 weeks away and i want to know if anybody would know what this could be. anything would be very much appreciate.