With multiple results, an error in one won't mean a false result, as the other is tested as well to confirm it. The chance of both samples producing false postives or negatives is much lower than the chance of one.
Yes, they will retest the first and test the second.
one day.
No. It's in the urine, but no one is going to test for it.
Yes it will.
one day.
They certainly can--they use an adulteration test.
Yes it will test positive for about one week
No
In a swab drug test, they will test your saliva for drug metabolites and in the urine test, they look for the same thing, but in your urine. (PS. drug stay longer in your urine, than in your saliva)
probably in a hair test but not in urine
One
one day.