Yes. If they are administering a hair sample test it will be left in the hair until it is cut off. So the amount of time will depend on the length of your hair. However, I am told that THC is a difficult and expensive drug to test for in hair. So they may not even test for THC as much as other "harder" drugs. Luckily it should not be in your urine, as long as you don't have a large amount of body fat. THC is fat soluble and chronic users that are overweight can show positive for quite awhile.