Well, there is some margin of error built into both the Kaplan and the GMATprep software. Can't really get around it.
Since your exam is so close and you can't reschedule it, the strategy is pretty clear - take the GMAT and do your best. I would stress about learning or cramming at this point but rather focus on high level strategis (e.g. Ale one question at a time, try to Eli,innate careless errors, etc).
You may be surprised with your final Score. There are flukes that happen when people take gmatprep. No reason to agonize - more value to keep it cool and calm.
The best part is that you have plenty of time for the new application season and even if you do have to retake, IR is pretty easy, and it is just a few hundred bucks, not with losing years of life over it. You life does not depend on this particular outcome.
Good luck on Tuesday!