Am I pregnant?

This may be a dumb question but I was with a guy and gave him a hand job and he came on my hand. I kind of wiped my vagina with that same hand and I'm becoming really paranoid because I feel like there's a chance I could be pregnant. I feel like I can't but then also feel like I can. I'm just very paranoid because me and my friend both did the same thing and we missed our periods but don't know if it is just because our period is irregular and very stressed.