Mhm, very interesting, I think maybe it is a problem of drug tests. I think tests are not so good or you cannot remember what you did last days hahah. You should try another test, I can suggest you to check
Drug test kits ... they have a lot of test on drugs, alcohol and so on. I am working in an alimentary company and we are supposed to pass the drug test each 3 months, sometimes I am afraid because I am smoking weed hahah and I do not want to have problems, for this reason I am buying drug test to know my results.