Dont put too much pressure on yourself thinking you must pass first time....for a week before my test i was thinking this, and it just made me more nervous. On the day of the test i just thought "sod it ...i can always take it again "....this seemed to work for me, and took away most of the nerves. Your examiner expects you to be a little nervous.
Dont worry....you're not on your own....most people are nervous.