If you're a heavy smoker like you say you are, THC is stored in the fat cells and will remain there for about a month after use. You can go to GNC supplements store and buy something to clear it out of your system faster. If they take some of your hair they will find THC in your system up to a month after regardless if you take anything to clear it out of your system. Urine tests are easy to pass so long as you use something to clear it. "Saliva drug testing tends to detect very recent drug use. Also these drug tests are harder to adulterate than the urine drug tests since the sample can be obtained under direct supervision" This is from wikipedia THC takes anywhere from 5-30 days to clear from the system If you get a positive test it does not mean the end of the world.