Sex question

Hi everyone, I'm in college (20 yrs old) and really do not have time to be pregnant. I am going to be having sex this weekend(losing my virginity), and I'm more nervous about getting pregnant than anything. I am on the progesterone pill, which I take religiously within 15 minutes of it being due, we will be using condoms, and he is going to pull out because he like to cum in my boobs. How possible is it for me to get pregnant?