I don't think I can get pregnant...💔

Lately I've been thinking that I can't get pregnant. The reason I believe this is because when I was young and dumb I was having unprotected sex with my first boyfriend for a year and never got pregnant. Then I got on birth control just in case I could the second year we were tofether. Well now that I'm with the man I want to spend my life with and start a family with its been eating me alive thinking I can't have a babies. Yes I'm still on birth control but there have been times that I've messed it up without realizing it and those times I didn't get pregnant. Now I'm not saying I'm purposely trying to get pregnant but if it happened I know I'd be the happiest person ever. I'm just afraid that once I completely stop birth control I won't be able to start a family for this reason. I see so many people having babies and it just makes me sad to think I might be able to have them...