20. No period. What are the chances of me getting pregnant?

I just recently started having with men. I am 20 years old and I am paranoid about pregnancy. The thing is, I have never had a period. I've went to the doctors but all they keep telling me is that I have too many male hormones. Yes, they have tried me on many pills, but none of them work. I just want to know is there a possibility that I can get pregnant, especially while using a condom. I am too young and I have too much going for myself to have a baby at this point. So, will someone please help me? I would like a second opinion besides the doctors. By the way, I just recently had unprotected with a man who said he had a vasectomy. I know it was very irresponsible on my part, but we all make mistakes. So, could I be pregnant?