Hi Doc, I Take Several Medications Which Include Inhalers,blood Pressure

Hi doc, I take several medications which include inhalers,blood pressure meds, plus many more. I also take Moriphine tabs. and liquid for pain. They make us test once a year to make sure we are in fact taking our meds, or at least thats what they say they test for, anyway the nurse came to me and said she needed to test me to make sure I was taking my Moriphine and etc. , said nothing about testing for illegal drugs too. Now I also take Sudephed and other meds that I have to sign for when buying. I take these other meds to help me breath due to only having 50% open passage in my nose. Well my test came back positive for meth and now they want to stop my moriphine meds saying I take meth which I do not. How do I argue this point with them and can the inhalers they perscribe along with the Sudephed I buy cause this positive test. I need help because it is very hard to convince them I am not taking meth. Don't doctors have to tell you they are testing for illegal drugs prior to test