I recently (1 and a half weeks) had sex for the first time with a girl. I was prepared. I had a condom, and I used it. I am pretty sure I used it right. It didn't rip, and I don't think it leaked over the top (it was spermicide so it would be hard to tell). I just keep thinking that she might be pregnant though. She isn't due for her period for about a week, and she told me not to worry, but she won't take a test. My question is, should I be worried? What percentage do condoms work? I have heard everything from 80%-99.9%. It was a Trojan w/ spermicide if that helps.