TTC with Endometriosis

I am 23 and my husband and I have been TTC since October for baby #1. I have endometriosis and irregular periods and have taken birth control for years to help ease some of my symptoms and I am currently on day 2 of my 5 cycle without birth control and it has been the worse one yet. Does anyone have any advice on the topic? It's also difficult to track ovulation so I have been relying on my bbt for that because I never know when my period will start and how long it will last, cycles are never the same length, and the pain is excruciating while I am on my period. I need some advice.