You know that there are other methods of drug testing, correct? Hair testing, a few different kinds that test fluids in organs, and several different types of urine drug tests. It would have been a better idea to request a retest or pay for one out of your own pocket.

You are correct... not only can a hair test show you've taken drugs, but how long ago you took them. Urine tests are notorious for false positives.

OP shouldn't have to pay for anything. OP isn't the one that fucked up. The person that wants to tests done should use more accurate tests or multiple tests to begin with.

I agree that OP shouldn't have to pay for a test too prove their innocence, but unfortunately that's the only way that the vast majority of people who order drug tests would be willing to even consider retesting.

Denial ain’t just a river in Egypt.

If you don't specify which drug you tested positive for, then I'm going to go ahead and say this never happened.

Have you been eating many poppy seed muffins lately?

you'd have to eat like 1,000 in one day for it to show up on a test

That isn't true at all. http://www.snopes.com/medical/drugs/poppyseed.asp People have tested "positive" after a single bagel. There isn't 1000 seeds on a bagel.

Could you ask them to do a retest OP? Just to be sure?

Lots of things can give you a false positive. If you don't list over the counter and prescription drugs, you can fail a drug test for not telling them about those. Do some research

I've never failed a drug test before but I assume you could ask for a retest and find out what you tested positive for as well as give the people that are testing you. You should have talked with HR before you quit. Im sure there is a procedure for something like this. Hope you get you job back

Do your friends smoke pot? BC if they've smoked it around you the THC or whatever can remain in your system for up to 23 days even if you didn't actually partake in the the smoking.

this is only if you were in a sealed enclosed space, such as a car with all the windows up. also it's a small amount unless the marijuana is high grade. secondhand marijuana smoke in open spaces will not show up on a urine sample. I have no idea about hair, blood or any other type.

Maybe somebody in your workplace wanted your job. Slipped something in your drink, so you would test positive.

Poppy seeds can cause your results to come back positive for opiates. There are trace amounts of morphine and codeine that can be registered in the urine for up to 48 hours after consumption. Eating enough poppy seeds on a bagel or muffin can cause a drug test to come back positive.