Yes, I agree with most people mentioned, but I know (being myself a beginner) It's not easy, practice helps a lot, so practice in order to control every aspect of the kata. When you execute in front of the commission don't think about the outcome of the exam, don't think about people watching (and sometimes taking picture and movies) think only about the details of your execution. Good luck and until the day of the exam, keep practicing, even just by visualization, it helps I can tell you.