What to do about a drug test?

So this job called today and they are gonna hire me. Problem is, the drug test. I haven't done it in like 3 weeks but I did a little yesterday cause I was a tad pissed lol. I only took 4 puffs. But anyways, I REALLY want this job. So what do you think I should do? Borrow a friends pee, pee myself and hope it doesn't show up? Or what? I thought if it shows up I could hopefully be like " I haven't smoked in two weeks, and I stopped to get a better job" try to weasel my way out of it. Advice?