The best way to find out is to sit the exam and write it.
A bit facetious, I know, but I would say that many, many peole over-prepare. Not to say that is a bad thing, but there does come a time when writing the exam is a good idea.
People alway think that potentially failing a certification exam on the first time is like a scarlet letter they must wear for the rest of their lives. Lots of people fail on the first try. That usually gives them VERY clear direction on where they need more study, and were they can spend less time. It can also show someone how close they are to passing, and be a great motivating factor.
On the other hand, I see plenty of people 'schedule ahead' their exam, and be extremely surprised they passed.
Go and schedule!!!
Best of luck.
-Cameron McKenzie