Hi nastynaf,
By not taking any FULL-LENGTH practice CATs yet, you've made a bad choice. You shouldn't expect to be 'perfect' on your first few CATs - they're part of the training process and they'll help you to figure out if you have 'weaknesses' in any areas that are not academic (pacing, endurance, etc.). As such, you really should take one soon. That initial set of scores will provide important information on your strengths and weaknesses and you can use it to help you find the proper areas to focus on as you continue to study.
As part of your broader studies, you should plan to take FULL-LENGTH CATs on a regular basis (1 CAT every 1-2 weeks). Once you take that initial CAT, you should report back here with your scores and we can talk through the rest of your study plans.
GMAT assassins aren't born, they're made,
Rich