What Causes False Positive For Methamphetamine After Taking Levothyroxine, Methotrexate And Sulfasalazine?

Hello I take levothyroxin for my underactive thyroid, methotrexate, sulfasalazene for RA and had a head cold and took a couple of sudofed the next morning I had an interview for a job they said I got the job and told me to go give a urine sample that same day on the way home. They called 4 days later and said I tested positive for methamphitamine could any of these cause a test to be positive I need help here because I need the job and really if I was on meth why would I go right in they told me I had 48 hrs to go. Thank you My prepaid CC is O I have not worked in 2 yrs