I was wondering if anyone knows the percentage at which you could possibly get pregnant from this. I'm 18 and the guy knew I wasn't on birth control. It was sort of a quickie type situation and he did pull out effectively but you never know, essentially. My period at the time was supposed to start in 6 days and I am currently pmsing but I know that could still mean nothing. I'm really worried because I know there's a 20% chance,I think, that I could be pregnant and I really can't afford to buy Plan B or morning after contraceptive.