Vitex

When is a good time to start taking vitex?

Hubby and i have been ttc for about 13 years without any success. I did manage to get pregnant in March of this year but had a miscarriage a week later at 5 weeks 4 days. I was actually on my 3rd month of taking provera and taking a supplement that i believe helped. I tried doing the same thing but it has not worked. This past month was my 3rd month on provera trying again but I didn't get a period. So i want to know if i can start taking Vitex immediately? P.S sorry for the long post