HELP PLEASE

Well, I'm sixteen years old.  A couple weeks ago, this bout from my school asked me out. He pressured me into having sex with him and I ended up losing my virginity to Him. I didn't want to.! And I told him to stop and he wouldn't. I don't know if he finished or not, and I can't ask him, because after this happened, he told me to act like I never knew him because he had a whole girlfriend!! So I started feeling weird, and I'm afraid I might be pregnant. I was on birth control ( for health reasons) so I'm hopeful that I'm not. Also, I'm scared that he might have had something (std or something) I told my aunt and she was disappointed, but she said she would help me. I'm so scared and depressed I just need some advice.