Nah, they do allow some small amounts of THC because even non-smokers often inhale some by accident. And I find it pretty hard to believe that enough THC could get into your sample by sticking onto your fingers for a full 45 minutes, not rubbing off on anything in that time, thet rubbing off onto the syringe and then into the urine sample in an amount large enough to be traceable. And whether the results are positive or negative wouldn't affect how long it takes them to return the results. Just mellow out man, you don't have anything to worry about.