If you're hitting a plateau, but you think that you can improve, you should reschedule the test. If it's a true plateau, though, more time spent will probably not change the outcome.

If your score isn't changing, you need to change the way that you're studying:

- Have you been keeping an Error Log / Review Log for every mistake you've made? This is the #1 indicator of whether scores will improve. It's not enough to know the content; you need to know yourself as a test-taker. What mistakes are you prone to? What can you change about your process to fix those?

More here: https://www.manhattanprep.com/gmat/blog ... -studying/

- Have you simply been taking practice tests, or have you been working on specific topics and specific strategies? Practice tests will measure your improvement, but they aren't very effective for helping you to work on particular skills, say, for example, Backsolving: https://www.manhattanprep.com/gmat/blog ... m-solving/

- Have you been monitoring your timing and your mindset during the test? Make sure you're balancing your time, breathing, and making good decision about what to commit to and what to skip.

Also, you should plan to take 2 tests regardless, so it might not hurt to take one in 3 weeks, then try again a few weeks later. Here's why: https://www.manhattanprep.com/gmat/blog ... mat-twice/