Going to a fertility dr

On September 15. I'm nervous and excited. I just want answers at this point. Can I or can I not have kids. I know I'd be so heartbroken if I can't but I just wanna know. I've had 3 BFP when I miss my period and then a week later I get AF. It's so heartbreaking and I feel so worthless as a woman. Why do our bodies go through so much. Why can Crack heads who could care less about their child get pregnant so easily when someone like myself who takes care of their body can't seem to ever have anything go their way. Ugh lol

On another note. If you went to an infertility dr what were some of the things they did with you? What questions did you ask? I want to be prepared when I go in there to get as many answers as I can.

Thank you in advance for any advice.