What are the chances of me getting pregnant by pre cum, I just got off my period

I lost my virginity a week ago, and I'm starting to worry. Well, when we started he stuck it in with out a condom after not even a minute pulled it out and then went back in for less then a minute again, then put on a condom and had sex. He did not ejaculate before we started, but did ejaculate after in the condom. I'm just scared that I could be pregnant, by pre cum. What are the chances of me getting pregnant by pre cum, I could I be pregnant? Also, I had just gotten off my period when we did it, so I won't get my period for about 3 more weeks which makes this even scarier