PCOS life after birth control

In January my ob/gyn doc told me he believes I have PCOS making it not impossible but very difficult in conceiving. I was put on a 28 day birth control pill to get my body regular with my cycle. After 4 months of the pill I am now off the pill and ready to start trying to conceive again. How long until the birth control is out of my system? I am afraid becoming irregular again will prolong this process even longer. Any one have any advice or experiences?