What Happens if I Failed My FIRST Drug Test During Supervised Probation?

I was put on supervised probation for charges of theft under $5000 to support my opiate addiction, they are aware it was because of my opiate addiction. I went for my first drug test and they found THC in my system, what happens now? Does it make a difference that it was my FIRST drug test, and my first time on probation, along with my first charges on my record? I live in Canada and just turned became an adult, just got a fulltime job, am graduated, and am starting to attend AFM meetings as part of my probation in two weeks as well.