It's unusual to see a big score jump from your performance shortly before the test to the real test. It can happen sometimes, but it isn't the typical case.
Since you've already paid for the test and it's too late to reschedule it, you might as well go ahead and take the test. Consider it a practice run - a chance to see how the testing center works and to get one test experience under your belt.
If things go extra well, then you may hit 600+. (And maybe that's good enough? you didn't mention your goal) I do notice that, on your last two tests, you had one with a higher quant score and one with a higher verbal score. Do you know why your scores flip-flopped like that? If you can figure out why, then there may be something you can do to increase the chances that you'll be at your top quant and verbal going into the real test (though you may not be able to figure this out and take the necessary steps in only a few days).
If you need to take the test again, then we need to talk about how to study for the test in a more effective way.
[I recommend doing this next part after you have taken the real test.]
Let's start with an analysis of those last two tests to figure out why you get a much better quant score on one and a much better verbal score on the other. Think about any differences that you're aware of between the two and also look at the data for both tests.
Next, read these two articles:
https://www.manhattangmat.com/blog/2013 ... lly-tests/http://www.manhattangmat.com/blog/2013/ ... -the-gmat/Think about how what you've been doing does and doesn't match up with that and how you may need to change your approach accordingly.
Then, use the below to analyze your most recent MGMAT CATs (this should take you a minimum of 1 hour):
http://tinyurl.com/analyzeyourcatsBased on all of that, figure out your strengths and weaknesses as well as any ideas you have for what you think you should do. Then come back here and tell us; we'll tell you whether we agree and advise you further. (Note: do share an analysis with us, not just the raw data. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)