I may have a drug test coming up for a new job. I have a Percocet left over from a prescription given to me a month ago, but I am not sure if they will accept that as a valid prescription if it shows in my drug test, since it has been just over a month since it was written. How long would it be before it would not show up in a drug test? Any idea what the general guidelines for drug testing is? If I can prove it was a prescription written to me, from my doctor, do you think they will accept it even though the prescription was written a month ago? The ER prescribed me Lortab 5 for the pain I am having, but it doesn't seem to be helping me much, so I figured I may want to try this Percocet I have left over... Any help would be greatly appreciated!!