am i pregnant please help me

I'm 14 and my boyfriend and I had relations on August 3, I'm still a virgin but when I was in the dressing room he came in and things got a little heated up and he moved my underwear to the side I bent over and I had a moment of reason and moved, his dick did touch the back of my butt around the anal side and I think a bit around the vagina, he didn't cum he just had pre-cum, my last period was July 12ish, and I still haven't gotten my period help!!!, I've had many cramps and mood swings to estimate I would be 4 weeks pregnant If i was (hoping I'm not ) my period hasn't come that's my main concern my breasts do get tender and I start eating more, it's probably all in my head um just really scared please help me someone