Your best bet is to get some Quick Fix and substitute. Amazon usually has them for under $20. Might cost a little more to overnight it, but it will probably be worth it. Chances are, you will have to take the test tomorrow on your first day, so you might be SOL, but hopefully there's a couple day lull in there and you can get some QF. If you can't, I would find someone that has clean urine, but your only truly safe move is to sub IMO.