What are my chances of passing this drug test?

a lot of times they don't even screen for marijuana because so many people do it. But if it is at a hospital they might. It probably won't still be in your urine after a week, esp with the small amount ingested so you should be good. Hair is another story. Good luck. The B vitamin stuff is crap (that has nothing to do with how fast your liver metabolizes it or doesn't metabolize it) and it doesn't stay in your hair forever, it's about 3 months.