Will I be drug tested at training for amazon(my first day). I already passed a mouth swab test?

lots of individuals have been taking a mouth swab test and passed the test if you think this test would be the best way of drug testing causes has dna better at times then other tests if you passed that i don't think there is much else to worry about as far as drug testing goes there are alot of jobs out there that do the ua testing so i think your fine if they suspecting something i think they would do the us instead of the mouth swab