My girlfriend started freaking out...?

i'm 17 and my girl is 15. last night we had , and it was her first time. after we finished she came to me saying that she was bleeding, i told her that was suppose to happen, but i could tell she was unsure because her eyes started to get all teary, which made me feel bad, because i don't want her to regret having with me. by the way i've never taken a girls virginity before. But my question is was she really suppose to bleed or did i do something wrong.