Well you still sound good and you did the right thing filling out the background paperwork. It's going to be a tuff call depending on how long ago you were charged and your age. Passing this drug test will help show you learned your lesson.

I was one of the first people here to link that qf failure post from the other forum and one problem was that person tossed the box and paperwork out. If he didn't give them a reason to suspect his sample then the qf may have been old or stored improperly and something was off with the chemical makeup.