Why hasn't it happened yet?

I'm curious as to why I haven't gotten pregnant yet, I already have a 10 year old daughter but trying for baby #2 I've never used birth control, we've never used any sort of contraception in the 6 years we've been together and have only been actually trying for maybe 7 months, could something be wrong? I'm so afraid that that's the case I don't want to go see a doctor, I make the appointment and cancel last minute because that fear is bigger then me, I don't want to hear that I can't and have my dreams shattered. Im following the tracking system so I'm not sure why else I can do I'm in shape and eat healthy.