Drug Test Stress...can u help me??

Here is my issue...

I have a drug test tommorrow, and I would like to know what my chances are of passing. I smoke fairly potent weed about once a week, but I have not smoked in six days. I weigh about 155 and I am 6'1". Am I gonna pass???? I intend to drink water to dilute my urine and take vitamin B Complex to color it yellow. This leads to my next question...in a simple urine test, not done at a lab, do they test for things like creatine levels and will they be able to tell if my urine is diluted by looking at the strip even though my urine is yellow??

PLEASE HELP

anyone with drug test experience please help me out