FWIW this is the timing of a drug test from drugs.com: How long does it take get workplace drug testing results?
Results from workplace drug testing are fairly quick and can usually be received in a few days. An employer may also request to have the test done with a rapid test that can provide results on the same day. Negative results are usually received within 24 hours; however, a positive screen will require further testing that may take a few days up to one week. If the initial screen is negative, a medical review officer (MRO) will contact the employer with the results. If a positive result occurs, a MRO will contact the applicant for further questioning. It is important to notify the laboratory or MRO of any medications currently in use, including prescription, over-the-counter or herbal medications. The applicant may have to provide proof of a valid prescription for prescription medications.
https://www.drugs.com/article/drug-testing.html