Hi phurida29,
Most Test Takers can't "luck" their way into a 700+ on Test Day. Since you're fairly close to your goal, but you haven't shown that you can consistently score at that level, it's not likely that you would suddenly score at that level in 10 days. There's certainly no harm in taking the GMAT as scheduled, but if your goal is a 700+, then you'll likely end up taking the GMAT again (and spending another $250). As such, it might be better to pay the $50 rescheduling fee, push back your Test Date and continue studying. If you don't care about the $250, then you can certainly take the GMAT as scheduled (and you can always cancel your score it you're not happy with it).
I have a few questions about how you took your CATs:
1) Did you take the ENTIRE CAT (including the Essay and IR sections) each time?
2) Did you take them at home?
3) Did you take them at the same time of day as your Official GMAT?
4) Did you ever do ANYTHING during your CATs that you couldn't do on Test Day (pause the CAT, skip sections, take longer breaks, etc.)?
5) Did you ever take a CAT more than once? Had you seen any of the questions before you took the CATs?
GMAT assassins aren't born, they're made,
Rich