I Just Tested Positive For Methamphetamine And I Have Never

I just tested positive for methamphetamine and I have never used any kind of street drugs. I am so upset cause i know in my heart of hearts and am safe with my God that I am not guilty of this yet my pain Dr. refused to treat me but even worse than that I have to clear my name it is eating away at my soul. I take klonipin 2mg 2 times daily, Adderrall 30mg twice daily, Synthroid 200 once daily, Prozac 20mg twice daily and I have been taking claratin for about a week. I explained all of this to my Dr. but he said that none of that explained the Flagged drug test. Can you give me an answer please?