Can I get pregnant from being fingered with precum?

Me and my boyfriend were fooling around and he rubbed his penis on my vagina for a few seconds, then he fingered me quite roughly. I'm not sure if he actually had precum on his penis or not because I was wet and it could just be from the vaginal lubrication secreted when aroused. But he fingered me quite roughly and afterwards there was a little bleeding which I think was the result of him being too rough. For the next 2-3 days I've had slightly brownish discharge and I researched and it was possible that it was leftover blood or something but it was gone after 2-3 days so I didn't think much of it. The problem is my period was due 10 days ago on Apr 9, but my period has never been regular though. My last period was on Mar 9 and ended around a week later, around Mar 15. The day we fooled around was on Mar 20. I've done extensive research and I have not been feeling nauseas, urinating frequently or having my areoles becoming bigger and darker but there is still the risk and this is really affecting me badly because my exams are just around the corner. Can you get pregnant from precum? Please help!