Fertili Tea with Vitex

I am just curious if anyone have an experience with this tea... I have heard that Vitex is very helpful for irregular periods. We have been TTC for over a year now, and I have not been on birth control for over 4 years. I have had regular monthly periods for years and have been taking opk for several months and have been getting positive OPKs. I have been speaking to a midwife that we plan to interview and she recommended this tea to help increase fertility. I have read very good reviews and I have also read reviews that if you have a regular cycle it could cause you to go irregular.