I Hooked Up With This Guy. We Made Out And

I hooked up with this guy. We made out and were fully clothed. I was slightly on top of him. I then gave him a blowjob but I still had all my clothes on. I believe he ejaculated but I am not sure. I turned away and I think he may have touched himself there. He then grabbed my butt. Is it possible that some of the sperm in his semen got into me? Could I be pregnant? Please help I am really stressing about this and I am very scared. I am only 15.