Should I be worried or just relax

I had sex a couple days before my period I’ve recently lost my virginity to my boyfriend we had unprotected sex 3 times but he only came the third time we had sex once he pulled out he didn’t nut inside me I seen him pull out n nut but I’m kinda worried because I’m 4 days late on my period I feel like I’m bout to start but it’s just no blood , can sex mess up my. Menstural cycle ?