help!!!

today was the first day of my fertile window and i had PROTECTED sex with my boyfriend . he still pulled out and he finished in my mouth. then about a minute later he tried to put it back on with out a condom but i don't think he got it in because i made him stop since i remembered i was fertile. is there a big chance of me getting pregnant if he got it in? even if he didn't cum? what if there was something left from before???