Could this be endo or something else?

So, my periods have always been painful since I started when I was 11 years old. Sometimes advil works, sometimes I need 800mg of ibuprofen every 4-6 hours but ONLY for the first 2 days of my cycles. It seems like every other period is awful with cramps and jelly-like blood clots. Gross, I know. Last year my hubby and I decided to TTC and have been unsuccessful so far. A few months ago, I started having bad low back pain (I exercise 5-6 days a week - mostly run) and it seems to hurt more when I'm sitting. My family had bad backs and my mother and grandmother swore they had endometriosis, but were never formally diagnosed with it. In between my periods is fine, with minor aches in my groin area. I get ovulation pains and it hurts to have sex when I'm just about to ovulate. But, it's fine other times throughout the month and I have no pain during sex. My gyno thinks I don't have it, but my RE thinks I do. So, I don't know what to think. We are waiting to see if we conceived this month with <a href="https://glowing.com/glow-fertility-program">IUI</a>. If we aren't successful, I am thinking of doing an lap surgery, but I am hesitant since it is not always successful. Anyone have any of these same symptoms? Thank you!