If they don't know you smoke and you are just acting really tired they probably want you to have a CBC (don't know if it's called that in Australia) but it is a Complete Blood Count...checks the red and white blood cells, platelets, hemoglobin, hematocrit, all the good stuff. They probably want to make sure your not anemic or something that is making you actually sick. A CBC or similiar test does not check for drugs so you're fine there. But if they're suspicious of you using drugs and you don't want them to know then you should def chill for the next week or so. Better safe than sorry. SO as long as they are not drug testing you should be fine. Good luck! :jointsmile: