Ttc questions

I have been trying to convince for about 5 months now. I recently set up a doctor's appointment just to get myself checked out, I have a new doctor and I want to be completely honest with her. Buttttt I am nervous that she will not take me seriously because I am only 18 years old. I have no doubt in my mind that I'm not ready for a child. I am engaged and life couldn't be better right now. Just need help on what to do! Do I tell her or do I just ask her to take a look into my health.... Do sent help that I'm overweight so she'll probably just tell me to start trying to loose some weivbt. Ugh I'm nervous