Infertile fear

One of my biggest fears is being infertile. I'm only 16 and not planning in having kids until I complete medical school (aspiring pediatrician here) and my boyfriend isn't even sure how he feels about having children but I love kids. I babysit a lot, I have a baby niece, and I volunteer in a nursery and the baby fever is strong. I'm just afraid I'll come to find I'm infertile. I know there are other options, I just really want to do things the natural way and carry my baby through those 9 months. Its silly and I don't talk to anyone about it but I do wish I could get myself checked out