Why Did My Mouth Swab Drug Test Show Positive For Meth But Not For Adderall?

Hello, I’m on adderal for adhd and I went to a pain management doctor for back pain. He did a mouth swab drug test and it came back as positive for meth and did not show the adderal that I’m on. I take some antidepressants also prescribe and I also take floanase for allergy’s. Do you know what caused this cause the doctor won’t see me as a patient because of this and this could cause problems being on my record. How can I get it off my record. Thanks