What is the procedure for a positive result in a UA in National Guard?

I recently underwent a 100% UA at my unit. The test will come back positive for an amphetamine. I am prescribed it by my civilian doctor, so I am not worried about any repercussions per say relating to a positive test since I have the prescription that is authorized in the DEA Controlled Substance list. My question is the timeline and what the procedure is afterwards. My biggest worry is that since due to my civilian job I travel a lot. The next two weeks following the test I will be out of town unavailable. Do I receive a call then immediately have to report to the CO or given a few days or next drill weekend? That's my dilemma since if it's an immediate thing then that would pretty difficult since I'll not be within driving distance but in Puerto Rico those two weeks. If it's next drill then of course that would be no problem.