Should I be mad at my girlfriend for this or did I over react?

I'm 16 and I just got a girlfriend that I have always wanted and we have lasted a month so far its been really fun a good but something happened the other day. We were talking on the phone and the subject of came out she ask me if I was a virgin I said yes cause I am, I ask her the same she said "hmmmm no I'm not but I really rejected it". When she said that I felt something wried and I have looked at her different my best friend who is her cousin said "bro she call me crying that she think you gonna break up with her". I am mad at her but I like her to much for this to end what should I do? Should I be mad?