My boyfriend and I has sex on December 28th. Half way through intercourse he wanted to change our condom because he thought it was getting dried out. When he was putting on the new one he accidentally put it on inside out but before fully putting it on he flipped it and put it on the correct way. We continued to have sex but should we be worried about precum? He peed before we had sex and the last time he ejaculated was the day before. So would the urine take all traces of sperm left in his system? Should I worry about pregnancy? My period is due on January 5th so I did have sex close to my due date. Condoms had no spermicide.