I took 3 mgs xanax 17 days ago on may16 and had a drug test yesterday june1. I don't usually take my perscription only as needed for anxiety and panic attacks. I took it the first time 17 days ago since the last time back in march. I know if you take it on a regular basis it can take a month to clear out but I don't take it on a regular basis. How long wld the one time use of 3 mgs of xanax get out of your system (urine)? And wld it be out 2wks (17) days later? Ive read a couple days and 6/12 hrs half life.