I take nucynta (tapentadol) and percocet for pain. i recently failed two drug tests because nothing registered in my urine. i take them every day. how is this poss?

Get the confirmation: If you are taking your meds as prescribed and your provider is only doing a read-the-cup-in-the-office color-change test, then ask for your samples to be sent to the lab for urine drug screen confirmation. If you have a false-negative and are being threatened with discharge for noncompliance, then ask for the official reading. It's expensive, but you'll get to stay in your program!