I think I can't get pregnant.

We haven't been ttc but we have had always had unprotected sex but there's been a couple times where it happens on the ovulation day or days before and it doesn't happen I think it's me but it's been like 4 months and I keep thinking I can't have kids. I get my period regularly like this month we had sex 2 days before ovulation and I'm on my period. I'm a little sad.