I was taking Nyquil, Albuterol inhaler, Vicodin, Phenergan and Macrodantin; all of which were doctor prescribed. I had to take a drug test which resulted in a false positive of Methamphetamine/Amphetamine, which I absolutely was not taking any such types of street drugs whatsoever. Could this be due the combination of some of the prescibed meds I was taking. Which ones and how do I prove it otherwise?