i had this same problem.

don't even bother making sure you're clean.

i smoked right up til the day before "beginning of diversion meeting" and it didn't matter because i'd been caught with marijuana. my diversion meeting was in march, and i had got caught in december.

my diversion supervisor didn't care that it was in my system.

however, she marked down what level the THC was in my system, and if i ever went over that, or had a decrease then sudden increase in the amount in my system, it was pretty obvious that i'd smoked.