TEST ON FRIDAY, (PLEASE HELP!@#)

Its now 7:00 am, and I am exactly 12 hours clean.
To make this as easy as possible, (I know you mods, and other frequent posters deal with these threads a lot, so just please answer my questions and then you are free to close/delete this post)
background: I am 5'5, 125 pounds. Very little body fat. I bike, and walk everywhere. I walk places around my town, no more then a couple miles away though, (no car atm:[ ) and I bmx bike constantly almost except for the last 2 days I have had a flat tube.
habits: I smoke weed. a lot of weed. I also occasionally (just got off of an addiction) smoke a cig or two. I have been pretty much smoking hardcore for about a year. I've had about 3 breaks, once because I got locked up for doing stupid shit while on probation (not on probation anymore, probation was 3000 miles away as i moved from michigan to arizona) well that was a 5 day break in the begening of february. I got locked up again for other stupid shit (not drug related) for 2 weeks in april. june 26th, I moved to arizona and had an exactly 60 day break. Now from sept. 26 to now, I've been smoking a lot, not taking more then 1-3 day breaks every couple of weeks. It is now December second, and I (like I said above) am 12 hours clean, and at 7:00 exactly tonight, I'll be 24 hours clean. My test is on friday, at a lab. (not sure of the times.)
I can't use synthetic urine because they watch me piss, and already warned me that they do this. I also don't want to drink mass amounts of water to dilute/get a re-take date, unless thats the last option above failed test. If I follow the stickied guide to pass a drug test, would I be in the clear? I'm saying this because I only have like 3 1/2 days I can possibly be completely sober on. (I am not a "weed addict," but I smoke because of insomnia, add, and depression symptoms that vanish when I get "high.") so would it even be possible for me to pass this test, or should I get the water flowin' asap, to try and get a re-take date?

Please help all, would be greatly appreciated.

I would try to stall the UA if you can and get a couple cheap thc test strips. Read and follow the dillution sticky.

if i was u i would dilute...there is really no way to be clean in that short of time.. and it wont matter if u start drinkin water now..u have to wait till the day of the test..and drink TONS of water about 2 hours before the test...make sure u piss like 5 times before u go to the lab...then make sure not to smoke and when they call u to tell u its diluted hopefully your pee will be clean by the new UA date..

good luck man..

well mods can delete this thread, i ended up going YESTERDAY and failing horribly. lol.
well ima just not smoke and pass my next ua i guess.