As a Chronic Pain sufferer I understand your question very well. The reason the doctor has ceased prescribing you percocet is because a prescription is meant to be taken as directed. As opiods only stay in your body for a few days, the doctor has made the assumption that you are either taking the medication improperly or are selling them, because if taken correctly the levels of the drug should be detectable in a standard urine test by the time your next scheduled appointment comes around. As it sounds the levels were not high enough for detection, thus the reason for the cessation. Hope this helps... If you are indeed in real pain search out a new doctor, I personally have come into situations such as this in the past, your easiest option is to try a new doctor (however make sure you have totally completed buisness with your previous Doc as DOCTOR SHOPPING IS ILLEGAL [punishable by up to 5 Years per Doc])