Am I Just Overthinking??

Okay-my boyfriend and I were nude from the waist down and fooling around in bed the other night. We had oral sex, nothing new, and then we were grinding with still nothing on. We are BOTH VIRGINS. His penis was just rubbing around my vagina. I know for damn sure that he didn't cum in me; but is there any way that pre-ejaculate could have gotten inside of me or got on me and went in and got me pregnant? I am super duper worried. According to this app too I was ovulating at this time. But I didn't even think pre-ejaculate had sperm in it and if any a very little? He peed as well since his last ejacualtion if that changes anything. 
Just please ease my worries and tell me everything is okay?!