What to do if i had a false positive on a drug test, is there a chance i'll still get hired?

Not if they think it: is positive. Companies that operate ethically should have a drug testing policy that requires confirmation of any positive on a screening test. The confirmatory tests, at this state of their development, DO NOT HAVE false positives. If you tested positive, and they confirmed the test with a sophisticated method the way they should, it means YOU USED THAT SUBSTANCE. So I would say stop using.