Should I cancel my appt with pain mngmt doctor? I took a suboxone a friend gave me.?

I know this was not particularly wise or safe but I have been dealing with non stop chronic pain for 3 months now and just got to a point I was so desperate for some relief I caved. I have a ripped disc and after trying accupuncture, chiropractic, tylenol, advil, hot/cold therapy, hot tubs, physical therapy I was finally prescribed lortab 7.5 2xday for the pain. I would get a maximum of 2 hours pain relief usually more like 30 mins and in btwn was tourturing my liver taking more tylenol. I explained to my doctor I was getting NO relief. We did 3 trigger point injections and an epidural that worked for a bit but as of yet still no success. I am depressed and angry all the time. Like I said a friend who has chronic pain gave me a few of her pills to try and I did get better long term relief (12 hrs) with 4 mg suboxone. Well I finally found a pain management doctor who will see me and my appointment is in 10 days. After doing some research i have discovered they typically drug test you at your initial consultation. Great. So have I totally screwed myself? If I go to the appointment and they discover this unprescribed medication in my system it will mar my medical records and the doctor prescribing me my lortab ( which when its all you can get I"ll take it over nothing) will be notified. Is this an accurate umption? Or will they not test for suboxone at an initial appointment? I have no experience with pain management doctors but it sounds like the tiniest error in taking your medications as prescribed will cost u for the duration of your life. Can anyone give me some advice or insight on what the initial appointment is like and if the suboxone is likely to be detected?Please no reprimanding me. I know it was a very foolish/dangerous thing i did but I am truly just desperate for pain relief so I can resume my life as it was prior to this injury. At present the only relief i get is laying on my back 24/7. which is no life at all.