21 days you should be good.. if you have a fast metabolism. Drink some orange juice and a bunch of water afterwards(not to much you don't want to totally delute your urine and come up inconclusive). Use the middle stream.. I mean start to go for a minute then do your catch. remove then finish urinating. I have learned that if there is any THC in your urine it will be in the beginning or the end of urination. It usually only takes 5 to 7 days to clear from most peoples urine. It stays in the blood for 30 days from my research.