Hello!
If your bf put his hands anywhere near your vagina with the pre-cum on then you could get pregnant. Also, if he inserted his penis inside your vagina without a condom on then you could get pregnant. It doesn't matter that he didn't ejaculate inside you, the pre-cum could still get you pregnant.
If you've got your period then I would say it's unlikely you're pregnant but you could test just in case.
In future, make sure you use condoms and it might be a good idea to go on the pill as well, so you know you're doubly protected.