Has Anyone Ever Gotten Pregnant This Way?

boyfriend and I saw each other and that was on the 5th day of my period, today is the last day of my period. We were both pretty driven to get intimate and he was smart enough to know that even if we don't have vaginal sex I like for him to wear a condom. Throughout the whole evening I had a tampon in. He did in fact pee since his last ejaculation before we started doing anything. Before he put a condom on he would touch himself and then touch me-but never fingered me. It would be either playing with my clit or butt. When we were ready he put a condom on and made me comfortable and we had anal sex. This wasn't the first time that we have done it. He ejaculated inside the condom and threw it out properly. What are the chances that when we were screwing around beforehand that I could get pregnant? Could precum get around my vagina and through my tampon and get me pregnant?