Scared, may not be able to have kids!

So I have an irregular period, sometimes I get it an then I don't. I always thought it was okay but I am in a relationship now and we plan on getting married in the future so I started doing some research about my irregular cycle and found a lot of stuff but I am really scared about going to the doctor to get everything checked out. I don't want to hear or even think about the possibility that I can't have kids.... What do I do???