UA on tuesday

I've already passed a few UA's.. One i got clean in 18 days for after smoking chronically for years. I have another one on tuesday and the last time I smoked was late August (it will be 21 days clean on the day of the test) and am not really too worried about failing.. I'm probably going to drink a decent amount of water/whatever is in the guide and do fine.. Anyway, I drank on saturday and though I never thought i'd be concerned with it i actually am. What test do probation officers usually administer? Because I know a certain test only detects for like 12 hours whereas another one can detect from 3-5 days (EtG test). Do PO's typically use this test or no?