Hi hammypancakey,
The scoring algorithm on the Official GMAT is far more complicated than most people realize. Since that algorithm is proprietary, no GMAT company has an exact match for it, thus CAT scores can vary a bit based on the 'biases' involved in their respective designs. The most realistic CATs available are the 6 from GMAC, but retaking a CAT that you've already taken is NOT a realistic way to assess your skills. Seeing even a few 'repeat' questions can 'throw off' the Scoring Algorithm and impact your pacing, energy levels, fatigue, etc. (meaning that they would likely all appear to be better than they normally would be). Thankfully, the CATs from Kaplan,
MGMAT and Veritas are all 'close enough' to the real thing that they will provide you with a relatively realistic score assessment (assuming that you correctly take the CAT in a realistic fashion), so you can use CATs from any of those sources during your studies.
For your next CAT, I suggest that you take a FULL CAT from one of the above sources and take it in a realistic fashion (take the FULL CAT - with the Essay and IR sections, take it away from your home, at the same time of day as when you'll take the Official GMAT, etc.). Once you have that score, you should report back here and we can discuss the results and how best to proceed.
Beyond that data, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) When did you begin your studies? How many hours do you typically study each week?
2) What study materials have you used so far?
Goals:
3) What is your goal score?
4) When are you planning to take the GMAT?
5) When are you planning to apply to Business School?
6) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich