Quickfix 5.7 used at labcorp

[Burnt Toast]

The Dr. said he would let the employer know the test was OK.
The employer contacted me 17 days after the test and asked what meds I was on because the test came back "inconclusive".

If the doc said the "test was OK", then this sounds like the employer is blowing smoke up your rump, perhaps in an effort to trick you into fessing up to any wrongdoing.

Never settle for verbal info. Get a copy of your test results. And dont fess up to anything. The burden is on the employer and/or the lab to prove (on paper) that any wrongdoing had actually occurred and how it occurred. A mere "test was inconclusive" is not sufficient - it must be stated why.