Hi MaxiLou,
A couple of years ago, GMAC set a limit to the number of times each person could take the Official GMAT. Currently, you are allowed to take the GMAT up to 8 times, but no more than 5 times in a 12-month period. In addition, you have to wait 16 days between any 2 attempts. The At-home/Online version does NOT count towards those totals though, so you won't "spend" one of your chances at the Official GMAT by taking the online version of it. Under current policies, your Official GMAT Score is valid for 5 years (regardless of which version of the Test you take), so you have the option to take your GMAT years before you actually apply to School.
Before I can offer you any additional advice for your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what dates did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) What is your overall goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to School and what Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich