Proof that we had sex?

Hi im 15 and im about to turn 16 in 3 months. My b/f is 23 and me and him have had sex before already. I thought I was pregnant so I told him to take me to get a pregnancy test so he did. He got me out of school we went to the clinic. The first thing the lady told us to do was to fill out both these papers. And it seemed wierd because I was just going to get a pregnancy test and the only person that they really needed information was from me and not my boyfriend. So I took the pregnancy test and it said I wasnt pregnant. so when we were done and everything, she told us to step in a office so we did and there was another lady that was sitting down and she told us that was statory rape and that they were going to report that to the social service and that they were going to send the papers that we filled out to that same office. But me and him never put or wrote saying that we had sex or that we were a couple we just to them by words. do you think if they dont got proof that we had sex do you think that the social service can do something to us? well so then I asked her what will the social service do and she said that they will come to my house and talk to my mom. But if they dont got proof that we reall had sex they cant do nothing right? Please help me and answer my question a.s.p Thank you and God Bless You!!!