Being Tested Soon

I am going to be having a pre-employment drug test in 5 days. It is a urinary drug test. I have been clean for exactly three weeks(21 days). I am 6'0, weigh 125 lbs and excercise regularly. I am very skinny and have under 10% body fat. Prior to the 21 days I smoked 3-4 times a week, 1-2 times each of those days. Over the last week I have been drinking 3 glasses of water/cranberry juice every day. Do you think it is already out of my system and I am good to go. Or if not, any advice of what I should. I would really appreciate the help. Thanks.

I would pickup a home test strip and test yourself.

And if I were to fail that, what would you suggest I do?

If you fail that you can sub with synthetic urine. Which is the best and cheapest way to go anyway.