I usually skip a month on my period, but this month i got light and dark brown discharge and sometimes old or fresh blood, its been 2 weeks & still.

Anovulatory bleeding: If you are skipping months, you are likely not ovulating. You are not having periods. You lining grows to a point where it breaks down some, but you don't slough the entire lining. This is not good. Eventually, you can have heavy irregular bleeding. It's important that you have regular periods. The easiest way to cycle is with OCPs. You need to talk with your GYN.