Am I Unfertilized? Unable to have kids?

I've been with my boyfriend for 5 years now. We been having unprotected for the last 4 years and we use the pull out method. I never once got pregnant in my life which I am glad but I am also worried that I may not be able to have kids. I mean the more you have unprotected the more likely you are at risk of getting pregnant, right? But not me, why?! A lot of people I know use the 'pull out' method and in a result they still ended up having a unplanned pregnancy. This just makes me very worried. Has anyone been in my situation? Did you ended up having kids in the end? Helppppp! I'm very stressed out. Me and my boyfriend are planing to have a child within a year. I need to know what is it that's wrong with me!