so I had a physical and drug test for school bus company being a mechanic. planned ahead and bought two test clear kits which are powdered urine you add water too. I also followed N2 guide ( don't remember if that is this forum) and took a gnc detox drink. the morning of the test I used two different first check drug test at two different times about 2 hours apart, nothing showed up I was clean =). I went the same day, first to a meeting again with the company, then had a hour to have a drug test and physical by there place. from the papers I got at my meeting I found out I needed 2 oz of pee, my testclear kit was about 1 ounce. so when it came to the time I used my testclear kit and topped it off with my own urine. after the drug test I went to a store and got another firstcheck and I was still good. so now after the weekend I get a phone call that my urine was positive for marijuana ...... dam what did I do wrong ? top it off with my urine ? but I tested my self and all was good for the 50ng cut off of the firstcheck... idk what cutoff I was tested for I asked the guy that told me the bad results and they told me they don't know the lab does .. my urine was sent to a different lab by fedex idk the name or location