Hello. I had a hair sample drug test twice and failed both types, I was told I was positive for cocaine. I do not take illegal drugs , I take over the counter cough medicine and allergy medicine. So, I am wondering what could be in my system that can trigger a positive result. I look online about getting a gas chromatography or mass spectrometry from a doctor. So, I would like somebody to give me some insight on this matter. Also, what can I do to stop a positive test result the next time around. Thank you