Originally Posted by ZellaX

Don't worry too much, 3 weeks should be enough time. Don't waste your money on detox drinks, they don't do anything other than tell you to drink water and contain B vitamins to keep your piss yellow and electrolytes to keep the specific gravity up. Before you go in, drink a quart of Gatorade, don't use your first piss of the day (unless you are testing yourself), and give them a mid-stream sample. Make sure you don't dilute too much or you will fail and/or arouse suspicion. The Gatorade will help keep the SG high and will help with color also.

If you are concerned, order some drug testing strips from eBay, they are cheap and can give you peace of mind. Hope this helps...