I'm going to go to CVS tomorrow and get one of their at-home marijuana tests (that's the only drug I have any reason to be concerned about). I'll wait til about mid-day and then test myself mid-stream
When testing yourself each time, always use the first urination of the day, when THCA levels would be at their highest. If youre testing negative with the first urination of the day, youre good to go.

If you test positive, and the scheduled U/A is 3 days away, you have 2 viable choices:

- find a clean sample or synthetic to use as a substitute

- avoid all exercise and begin creatine-loading in preparation for dilution on the day of the U/A.

Read up on both the Dilution and Substitution "sticky" threads.