Hello. So I'm 15, And I Recently Had Unprotected Sex.

hello. so i'm 15, and i recently had unprotected sex. and he said he did not ejaculate inside me. but i was still scared for precum. so after we were done. the morning after. i went to the drug store to get a plan b pill. i took it around 2 pm on wednesday. and today is friday. i am ovulating a lot. and not sure if it worked or not. my period is very messed up. i won't get it for a long time and when i do, it's not that long. but i don't know if i would end up being pregnant or not. i do not have any pain or anything wrong with me right now. my period is very messed up and i'm not sure if i would be pregnant. does plan B actually work? please answer. i'm freaking out