Endometriosis.. how to get my doctor to listen ?

I have moved around a lot in the past few years so I have had multiple doctors. But the last two doctors I have had both said “it sounds like you could have something called endometriosis” but would never do anything to look into it.. they both told me to just take birth control and it would help the symptoms. Which it does.. BUT now I’m married and TTC and I’m worried I am not going to be able to bc I could potentially have endometriosis.. we are on month 7 of trying.. I’m only 23 so I figured it would be easy.. now that I’m off of birth control, I have uncomfortable pelvic cramping during ovulation, horrible.. like HORRIBLE period pains that make me contemplate going back on birth control and throwing my hands up and say forget it.. and on and off again cramping basically every day of my cycle. I am also ALWAYS bloated.. like people close to me just know I am always booted lol like it’s weird.. I’m 5’1 and 130lbs. And I can wakeup with a flat stomach but no matter what I eat or do I am bloated.. I have issues with constipation and just really bad gas and belly pains separate from the cramps, I’ve had an endoscopy and a colonoscopy but they found nothing and just told me I must have IBS.. then I went to the doctor this past summer because my bladder ached.. she ran a bunch of tests and again found nothing and mentioned painful bladder syndrome but that was the end of that... NOW I have moved again and we bought a house. I have new medical insurance and I am making an appointment Monday.. I just worry they won’t listen to me again and just tell me well it could be but do nothing.. I have seen many similar stories about how women struggled to get their doctors to listen.. I don’t understand why doctors are so weird about it but idk.. how can I prepare myself? Why tests do I ask for? I’m just sad because I feel like we are wasting time and heartache over trying to conceive, while I go everyday in pain, and it could all be for nothing because I might have something that is completely stopping me no matter how hard we try 😞