First off, I cannot go by anything on just reading your question.
1. How old are you?
2. Are you overweight, underweight, or normal?
3. How long have you known about having PCOS?
If your not having periods, then i suggest to see your gyn and research as to WHY your periods stopped. Are you sure you have PCOS? Are you on any medications for PCOS? You probably need medications like Provera to have a period, and possibly clomid or Fermara to help induce ovulation.
But before anything...see a doctor...even before you take herbals.
There are a few herbals that I have read about...and work in some cases. Try stuff like Raspberry tea, or Vitex...Chasteberry as well. Spearmint tea is another great option for PCOS to help with symptoms. Do your research.
If you have PCOS the best thing to do is to see a dr and get put on pills to help. If you are overweight from Pcos you can also try loosing the weight to help. Good luck