Wondering. YES or NO?

hmm.... wondering....should or shouldn't.
Today is Friday, as usual I woke up earlier to practice my piano. The moment that I woke up, I was thinking about, should I take the risk? The risk that I may fail.
It is the Grade 6 Piano Practical Exam. I haven't tell my teacher my decision yet. Plus, I haven't think about yet!
  So guys, should I take the risk to sit for the Grade 6 Piano Practical Exam?  
Grade 6 is not a easy Grade to pass. D: OR even distinction! Besides that, the pieces are not as easy as ABC!
I listened to my music classmate played before. It's quite hard! And the scales too! :X

On the way to the Music Center, I think the same problem again. Then, I got the opposite decision.
My mind was telling myself I can do it. -o- Kept comforting myself. I can do it!
Plus, the exam is around June; the PMR is around October.
Therefore, I think I can handle the pieces but not the scales. BUT I don't guarantee that I can 100% pass to distinction.

I think I will sit the exam. SO, how you guys think?
 SHOULD I?