I agree that you need to seek a 2nd opinion - sounds like the nurse practitioner that told me I was too young to have arthritis at 18 despite a family history, but Lyme disease was most likely what I had...... Nut job.......
As for the Vitex. I took Vitex before getting pg with both my pregnancies (this one was a total surprise as you can probably guess looking at my sig......
). For me, it worked very quickly. I had 2 cycles the first time and got pg the 2nd cycle. This time, I was taking it because it helps increase milk production - which it didn't do for me.
This is what I did. I started taking Vitex near the end of a very long (I want to say 60 or 61 day) cycle. I had a lap mid cycle and it screwed everything up (I think both the procedure itself and the stress of surgery). That was the end of March last year. I started my next cycle within a few days and I think that one was about 35 days. The following cycle I got my BFP.
I was also using red raspberry leaf (960 mg - 2 480 mg capsules), baby aspirin, Metformin (1500 mg), a multi vitamin, B complex, folic acid (400 mg), vitamin E, fish oil (1000 mg) and flax seed oil (2000 mg).
Oh, and with this pg, I was taking Vitex, multi vitamin, folic acid and fish oil.
Here are a couple links about Vitex:
http://www.ovarian-cysts-pcos.com/vitex.html http://www.early-pregnancy-tests.com/vitex.html
What natural supplements could I take? 
