Pregnant!!!???

So I’m only 15 & my bf humped me when he was naked (I was wearing lacy underwear) the app said that I had a 33% chance of pregnancy! He didn’t cum humping me but I’m worried that somehow pre cum could have gotten inside me. I don’t think his dick was near my vagina hole but I’m not positive. I’m very worried! Do u think I could have gotten pregnant from this? Btw this happened about a week and a half ago and I’m supposed to get my period in 2 days so I’ll be SO relieved if I get my period.