Coming out of lurker mode to help. Been there back when I was working 9 to 5s and know people who've done this in the last decade
If you can, get clean urine from a healthy dude your age or get the fake drug test penis they probably still sell in high times express delivered....
Find a smoke or "head" shop in your area, they will likely have tea, pills, or powder that will mask your urine so you can pass the test, it will may be kinda expensive.
IF YOU DO FAIL THE TEST... Dispute the test by telling the proctor (who will likely call to inform you) that there must be some mistake and that you don't use cannabis. Tell them you the only drugs you take are Tylenol, ibuprofen,Advil etc REGULARLY and Tylenol Pm nightly to go to sleep. They come up as false positives for thc all the time. Your test should be labeled inconclusive and you probably won't have to retest
Good luck