Irregular menstrual cycles.

I'm very irregular. I've gone to the doctor and they have prescribed me birth control,59 regularized my cycle. Unfortunately none of that has helped Any body know what else I can drink to regularize my cycle ? 
My usual period is 10-13 days. The least would 9 days. 
Sometimes I don't even get it for months. Sometimes I get up to twice a month. :/
Thanks in advance.