PLEASE be careful about the labs that do the drug tests. Not just bc of the cost, but because they actually need to be VERY sophisticated to get the correct results. I had no idea of this until about 5 yrs ago. A combo of the flu and severe migraine meant that I couldn't keep my reg pain medications down and I had a severe seizure. I actually lost 2 1/2 days, days I will not ever remember. The doctor at the hospital handled everything badly, including refusing to contact my primary care doctor and my pain mgmt doctor. She also had the hospital lab do all the drug testing. They normally only do the instant read kind and send the others out to a specialized lab, but she didn't want that.
The tests that she ordered came back positive for methamphetamine. I have NEVER even seen meth, much less taken it. By the time I got out of the hospital, she had given orders that my records were NOT to be sent to my doctors under any circumstances. Of course she cannot do that because she does not have the right. I had records sent to my pain doctor and he was FURIOUS.
If a lab does not specialize in the drug tests, it is incredibly EASY to get false readings, usually false positives. From the way she specified my tests to be done, she could not have gotten valid readings apparently. On top of that, the lab made some super common errors and what they registered as meth was actually the result of taking phenergan for several days and of being on methadone (an opiate) and suddenly stopping it.
My pain doctor explained how it happened, assured me that he knew I did not take meth, and as he had tested me a week before the seizure, he was sure that they just did it ALLLLLL wrong.
The tests are highly specialized and must be done very carefully. Most labs just don't have the expertise. Normal protocol for reputable labs and doctors is to do the instant read tests like you see on the tv shows and then to send the samples to a lab that only does drug testing. It isn't even extremely expensive. Cash patients at his office pay only $50 if they are only on standard medications and have never had illegal drugs in their systems. If you are found to have used any illegal drugs the testing goes up to $1000 or more for each time until you have 18 mos of only rx medications at appropriate levels. But the doctor would NEVER rely on a lab that did not specialize in drug testing as it can be super hard to figure out what is really going on. False positives are vastly more common than many people think.