Hi Ramit88,
In preparation for your GMAT test, it's important to know what your scoring level is. Take 2 reliable practice tests in the next week (try to do the first one tomorrow and the second one perhaps on Tuesday) and see what your score is. If you get about the same score twice, you know where you stand for the 28th. See my blog post about this subject on
www.superduperstudent.com.
Have you been studying with a focus on your weaknesses? Then it may now be time to work on your strengths. Become REALLY good at the stuff you're already good at. Get SUPER quick at answering questions that you can solve in your sleep. This will build your confidence and give you a sense of being prepared, instead of a feeling that you're still trying to figure things out.
Finally, a great tip for the day of the test is to
be nice to the testing center employees. They can help you
and hurt you in many ways, and you should hope for their support!
Good luck!