Anyway to make period come?

I haven't had a period since December 5th and before that it was September 5th. From what I know I don't have pcos or endometriosis. Doctors have always told me I'm fine. This is month 8 of ttc and at this point I'm ready for AF to come already so I can try again... Any tips? Oh and I started taking vitex a week ago if that means anything.