Sex...

I had sex with my boyfriend for not that long like literally 5 seconds it was my first time and when he pulled out he told me later on he had cum on his penis, is this pre-cum and can this get me pregnant still even when it was still on him? I was drinking that night and that lowers the risk of you getting pregnant doesn't it. I was only 9% likely to get pregnant but I'm a bit worried. Sorry not an expert, thanks for any comments xx