When should you start taking vitex?

We have been ttc for 5 months now and nothing. I realize this isn't a long time, but I also noticed I am extremely hormonal since stopping the pill. My periods were irregular at first and the past 3 months are somewhat more regular, however the acne is horrible, crying spells are horrendous, etc. I feel terrible and tired constantly. I've heard of vitex working for pms symptoms as well as potentially helping to conceive, however I don't want to mess up my cycles by trying this if I don't need to. Any advice?