Im 21 and trying 2 figure this thing out .....?

[a. k 47]

my current boyfriend and i are now having sex...i have never had sex with him before..but anyway..the first time we had sex he bent my over 2 "get it from the back" (not anus) any i started whining and crying .... (cuz it hurted so bad)..so he pulled out 2 see if i was o.k..when we checked i was bleeding and it was blood on the condom..but i have never had the happen 2 me before...so my question is what happened and why did it happen..... no other boyfriend i have had-that has never happened and im not a virgin...