Hi NoofSM,
You posted a couple of weeks ago that your score goal was a 600+. If that's still the case, then this CAT score shows that you're not quite ready to hit your score goal. Since you've waited until the last possible day to ask for advice, there isn't time to make any changes to how you approach the Test. It's also too late to reschedule your appointment, so here's what I suggest - you should go and take your GMAT tomorrow as planned. Since you probably won't hit your score goal, you should concentrate on the 'event' - pay attention to the 'details' of Test Day, so that you'll be better prepared to face the GMAT the next time that you take it.
With a 310, you have a LOT of work to do to score 600+, but we can put together the proper plan after tomorrow.
GMAT assassins aren't born, they're made,
Rich