Drug test rant

So I knew I had an interview coming up so I decided to stop smoking for a few weeks in case I got the job and they required drug testing. Well I get the job and at no point does he mention drug testing so I think sweet I'm in the clear, and went home to have a celebratory toke. Next day the interviewer calls me and says that he forgot to mention that they have to do a drug test......well fuck... I'm not freaking out and begging for advice on how to pass it or anything I'm just pissed that this is most likely going to cost me a job that I desperately needed. End rant I guess...