I Took Plan B, After My Boyfriend Had Ejaculated On

I took plan B, after my boyfriend had ejaculated on my stomach and while very little ran down my stomach, i washed off in the shower, and took plan B within the next hour and a half and then my BC pill and hour after. i was very paranoid since this occurred the day after i got off my period. But since taking the plan B i have been very nausea and have to pee quite often. Should i be worried and is this normal. We did not have sex.