I have to be tested weekly in order to keep my job.  

You are referring to occupational items, driven by codes the public is not subject to.

And I also used the word legal, as an employer if no laws are broken or going to be broken you have no right to inquire about the drug used.  Sure you can have drug testing done, but if the drug shows up that is legal and percribed the use of that drug will never be reported to you the employer, even if the use of that drug is against FAA code.