Hi Mekhs,
To start, a 640/Q49 is a solid Score, so it could be enough to get you into your first-choice School. As such, another retest might not be necessary. Since you have a specific School in mind, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. Those Experts should be able to answer your Admissions questions and help define the specific areas of your profile that could use some improvement. There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/All of that having been said, I'm sorry to hear that Test Day didn't go as well as planned. When these types of score drops occur, the two likely "causes" involve either something that was unrealistic during practice or something that was surprising (or not accounted for) on Test Day. Before we discuss any of those potential issues though, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long did you study before each of your 2 Official GMATs? For this 2nd attempt, how many hours did you typically study each week?
2) What study materials have you used over the course of ALL of your studies?
3) On what dates (or approximate 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 apply to Business School? If it's sometime soon, then what specific application deadline are you facing?
If you took your Official GMAT at a Test Center, then you might also choose to purchase the Enhanced Score Report. While the ESR doesn’t provide a lot of information, there are usually a few data points that we can use to define what went wrong on Test Day (and what you should work on to score higher). If you purchase the ESR, then I'll be happy to analyze it for you.
GMAT assassins aren't born, they're made,
Rich
Contact Rich at: Rich.C@empowergmat.com