Scared out of my mind

Thelma
So I'm 17, and I'm honestly very very scared. I've had unprotected sex with the same guy, 3 times in less than a week. I convinced myself that pre cum is just dead Sperm but I find myself looking up if it's true and I just end up scaring myself up. I have at least 3 period trackers downloaded trying to see when my period will come. I don't have family to talk to, they don't even know that I have guy , any less that I'm not a virgin. I don't know what to do. Someone please help.