I hear ya!! but not knowing metabolism, water intake, BF, I think the best advice is to play the safe side!! I pissed clean for marijuana 2 weeks after smoking and another time I pissed clean for MJ 10 days after a binge of heavy use while I had a vacation home for a few weeks, I must have drank at least 2 gallons of water that morning before going in for my test!! then I get popped again about 5 or six weeks later... thinking I had long since cleared it form my system when I got the call bright an early that I needed to show up for a piss test I figured I'd just go get it over with first thing... had been training hard an long the night before an was seriously dehydrated, piss was dark and it came back dirty I couldn't believe my ears when I got called in an given the news!! it was some legal shit an they weren't buying that I hadn't smoked!! I could have pissed dirty on my first go an been honest with them but I figured "why?"... but I was clean on my first go and dirty on my second... an THAT wasn't good!!! anyways point of the long ass story WATER intake has ALOT to do with piising clean!! haha!! along with other factors!!