I'm 15 and had unprotected sex - already the black sheep, they're gonna kick me out if I'm pregnant

I'm fifteen. I broke up with my 17-year-old boyfriend of 5 months a while back. But I stayed a virgin and kept all of his friends as mine. Anyways a few days ago I had unprotected sex with his best friend and lost my virginity and I'm really worried.

I'm already the black sheep of the family and they're gonna kick me out if I'm pregnant. I'm really paranoid. He pulled out I watched him. And he peed before we had sex just in case but my period has always been irregular and I can't track it to even know if I've missed one. This was so stupid of me.