Nervous And Starting To Stress!

I am starting to get nervous about the Uni Entrance Test now. At 10am next Friday I walk into the Exam Room knowing that what I do in those next two hours has a major impact on my future. My whole plan could fall apart miserably in those few hours and the worst thing about it is the fact that I can't study for it. You either have it or you don't. 
To this point I have been determined not to have a backup plan and I don't see the need to start worrying now but I have to admit that the thought has crossed my mind. I have the option to re-sit the test at the end of the year if my results are not high enough to guarantee me an offer after this one, but my concern is more that unless I blitz it this time around I may not be guaranteed entrance and have to re-sit anyway only to find out that my score would have been high enough after all the results are in anyway. 
So I may be doing my head in over nothing but we will have to wait and see. By the end of June I will have a better idea, or maybe not!