CD 49!!! No period and bfn.

This is so frustrating. I really don't know what to do to regulate my periods. I have been under a lot of stress lately and I am on the thinner side. I have been thin my whole life and have had irregular periods since I can remember. Makes trying to conceive nearly impossible. I have tried vitex, fertility supplements and eating healthier (more protein, fruits, veggies, etc). Has anybody with similar situation have good news yet? I have been ttc since July and just getting very discouraged.