Need Some Advice...how Potentially Fucked Am I?

Hey what's up GC, long time browser, just made an account to ask for advice or opinions on my current situation. I love weed, guys. I have smoked daily for roughly six years, skipping a total of ~10-12 days. Not proud, not ashamed, whatever. Anyways...I've got to quit smoking weed. I got arrested a year ago and am finally starting probation. Supervised probation. Truly not stoked about any of this.
 
So my sentencing date where I "officially" start probation, sign the paperwork, find out when I meet with my PO (could be that day, no idea at all) is on July 9th. Happens to be my fucking birthday. Also doesn't help that I still don't think I did anything wrong to deserve this bullshit, but that's not important. I'm doing the probation, and I'm not going to fuck it up by smoking weed. Well, I hope not at least.
 
I want to pass my first drug test. I know a lot of people say that it's totally cool to fail your first test and that there's a "threshold rule", so long as your levels continue to go down, you're good. I don't want to fuck with that. The way I see it, it sounds like extra drug testing ($$) and that my PO would likely be on my ass a lot more than if I would just get clean and pass the first one. Who knows, maybe if I pass a few they'll put me on unsupervised and get off my back.
 
Now here's my question. Do you guys think 2-3 weeks is long enough for me to pass a drug test? Key word is for me, based on the info in the first paragraph and the following. I'm 6', 180lb, pretty skinny/normal size so I've got a fast metabolism. Don't know if that matters much since I've been smoking for all this time routinely. However, for the last year/year and a half, I've started smoking a whole lot less. Definitely still daily, but just at night after maybe 7/8pm. I typically make an 8th last me 7-8 days. Also maybe one, two, three max times per week, I smoke with my friends, so we consume probably more like 2g total in one night. Again, this happens typically once or twice a week, rarely not at all and rarely more than that. The years before that I smoked more like an 8th every 1-2 days, so times have changed as far as my frequency of use is concerned.
 
I'm planning to quit Tuesday (the 18th) giving me 3 weeks until July 9th, when I  assume that I will have a drug test. Maybe they won't even test me when I sign the papers, but I unfortunately should be prepared. It'll surely be shortly afterwards if not that day.
 
Ya see though...I'd like to keep smoking a few extra days if 2-2.5 weeks would be a more than reasonable amount of time. There's some killer nugget in town so I would rather not miss out, but I also don't want to fuck myself over and piss dirty. 
 
So I'm asking you guys...is 2, 2.5 weeks long enough for someone like myself with my described habits to pass a piss test? Do I need to quit Monday and make it 3 weeks to be safe? I plan on exercising as much as I can over the 2-3 weeks and doing a little bit of dilution the day of the test. I also work a job where I sweat maybe 3 pounds worth of liquid every day.
 
Thanks for reading. Had no fucking idea this post would be so long, so I seriously apologize. Background details were necessary, but I probably could've tl;dr'ed it a bit. Any input is appreciated.

 

oh.

 

 
Thanks for all that man, I appreciate the encouragment, for real. I might PM you after I get off work if that's cool.
 
I probably should've just stopped a week ago, but from what I hear, it can linger for up to 2 months...assuming that's for super fat people, but what do I know. But anyway, too late now. My question now is, how can I get this shit "out of my system" in ~20 days? I know I'm not using fake piss or someone elses' piss on my first probo drug test, so that's out of the question. Is dilution my best bet?
 
Thanks again to those of you who read my post.

 

 
Lol that's probably an exaggeration, well definitely, but it sure as fuck seems like it. I work in a hot ass restuarant kitchen and walk 10-15 miles over the course of one shift.