Vitex results?

Ladies who took vitex to regulate long many cycles until you saw a difference? I am starting vitex next cycle to try and help regulate after stopping BC (stopped at the new year). 
First cycle 42 days 
Second cycle 60 days 
This cycle 43 and counting. Before Skyla (1year) and BC sprintec (8months) I had perfect regular 28 day cycles. So how long did it take your cycles to change for the better with vitex?