Should I change my dr?

I have been with my obgyn for about 4 years now and I love him. But I’ve never had a normal cycle and the only thing he’s done for me if try to put me on birth control. He says that all of my blood work is normal and he’s done transvaginal ultrasounds for me and doesn’t see anything out of the ordinary. I just feel like there has to be some kind of answer to why I dont ovulate. I can go 3-4 months without a period sometimes. What do y’all think I should do??