I failed my drug test and i had quit smoking poy for 6 weeks . what happened? how long does it take to cleanse my body?

Possible: If you were a daily user of large amounts, it could take that long especially if your body has a high fat percentage. (females usually do) should be negative any day. After 6-7 weeks, i would only believe in ongoing exposure.

A long time: Marijuana is a fat soluble drug. Depending on how much fat you have in your body, coupled with how much you used to smoke, makes a difference. It will leech out of your fat at a reasonably constant rate, even weeks after you have stopped using it.