Fear of infertility?

So I want to know if anyone can relate. I'm in my early 20s with no kids currently, and I never really had a reason to think I might be infertile, but for some reason I'm worried I'll never have kids. Even before i was ready but knew I wanted kids one day. It's to the point where I actually cry about it but bottle it up because I feel like I'm being dramatic. I had a friend say the same thing which helped me not feel so alone, and another who is a mom say that no one thinks they can get pregnant until they do. I'd love to experience carrying a baby and being a mom and I'm trying to calm my nerves which isn't easy. I don't know why I'm so paranoid.