Hey ,
firstly like skarya says u shud b looking at around 49 in your quant section.
secondly, dont make the decision of writing the GMAT again in a haste.
The GMAT only constitutes one part of an application. I agree you would like a better score there but do not pressure yourself. The key to success any such exam is a free mind. Because the moment you pressurise yourself you are gonna b unsure during the exam.
And any significant change would first appear on
www.mba.com . so if the guys there dont say anything there is no need to be worried
and Good luck ..