Drug policy question

Drug test question

I got randomly selected for a drug test today. I told my ASM that I have my medical card and he was like “I don’t even think Publix tests for marijuana” lol I googled it and found some mixed results, and he looked it up in Connection but we couldn’t really find a solid answer. The wording of what we did find was confusing and he basically assured me that IF my test comes back positive, I just have to “challenge it” and provide written documentation by my prescribing doctor.

Can anyone provide some clarity? Thank you in advance.