Well my GF and I were having sex on Friday night when all was going fine. Of course we were using a condom but it came off and was kind of stuck at the entrance to her vagina. I kind of laughed it off and just stuck it right back on not really thinking until after it was over. We kept going at it until I came but I didn't come inside her. Did I royally fuck up by putting the condom back on after it already came off? So how much of a chance is there that she is pregnant?