If you're a heavy smoker it stays in your system for about 30 days(assuming you stop all at once). If you aren't a heavy smoker, it takes about 2-2.5 weeks.

I have to get re-drug tested in about 12-13 days. I should be ok, I'm drinking a 16 oz. bottle of water every class period(I've got 7 classes). I'm also going to be drinking "Clear Flush" liquid the morning of the test. I just stopped smoking two days ago, so I'm pretty sure I should be ok.

Also, I've heard that the first and last little bits of your pee are tainted and the rest stays clean. I highly doubt this, but have any of you guys heard of this as well?