I am on probation and not allowed to drink a single drop of alcohol. I haven't had anything to drink, but had one shot this month. I instantly knew I screwed up, so I forced myself to throw up maybe 5-10 minutes later. I don't know if it all came up, but I assume some of it did. I am supposed to have a hair follicle test that tests for alcohol in December or January, maybe February at the latest. Will the test come back positive or am I safe? I heard it tests for frequent use and I have only had that one drink this month.

You'll be OK.

Though, you're not supposed to drink at all, as you yourself stated... stick with it and let this just be a lesson learned.

That amount will probably not register. There's alcohol in everything so you have to be above a cut-off. Even people who do not drink have alcohol in their hair.