Hi Mandar,
First off, a 690/Q49 is a fantastic score (it's just a bit below the 90th percentile overall), so it could be enough to get you into your first-choice School. As such, a retest might not be necessary. Depending on the Schools that you plan to apply to, you would likely find it beneficial to speak with an Admissions Expert about your overall profile. There's a Forum full of them here:
ask-admission-consultants-124/As far as how your Official Score compares to your practice CAT scores, GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function, your various results show that you have a general ability level in the low-700s (with a high of 750 and a low of 690), so your Official Score is 'in your range.' In addition, taking 3 CATs in the 4 days leading up to your Official Exam was NOT a good idea. Properly taking and reviewing a CAT requires a significant amount of effort and energy - AND takes time to 'recover' from. This is one of the reasons why you shouldn't take more than 1 CAT per week. By working through all of these CATs in such a short period of time, you likely experienced some 'burn out' right before your Test Day, which could have manifested in the Verbal section (since it's the last 75 minutes of a 4-hour Exam). It's also unrealistic to believe that you actually gained 50 points in 2 days during your final week of studying.
1) When are you planning to apply to Business School?
2) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich