Has anyone with unexplained fertility found out what was stopping them conceiving?.

Basically been trying for nearly 3 years and its been put down to unexplained infertility. I personally think I may have endometriosis but the wait list is so long on the NHS who knows when I will even find this out. The NHS fertility clinic say they can not help me and to go for IVF which has never been something I have been keen on. I just dont see the point if I do have endomitosis as I worry it would lower my chances and plus I have fibromyalgia and I just dont think my body can go through all that, mentally I am not there and I dont know whether I ever will be. I am trying to come round to the fact that maybe I will never have children.

I am just generally curious as to if anyone ever found out what was causing their infertility?.