Great job getting yourself up to 650. (I know you want more. I just want to acknowledge how far you've come!)
It's pretty difficult to move from 650 to 700 in 1-2 weeks—basically, the higher you go, the harder it is to go even higher. I know that's probably not what you want to hear but I do want to help you set realistic expectations. I still think you should still go for it—who knows! But, as you mentioned, you may need to take it a second time.
The key thing to do now is to figure out what your low-hanging fruit is—basically, the areas that have the best opportunity for improvement in a short amount of time. The first, best category is careless mistakes—how often are you making mistakes on things that you really did know how to do? What kinds of mistakes are they? Why are you making them? (eg, Did you do some math in your head and make a mistake? Did you transcribe something incorrectly from the screen to your paper? Did you answer the wrong question (they asked for A, you solved for B)? Did you misread something in the question stem or answer choices? Etc.
Another good opportunity is around time management—it's often the case that people spend too much time on certain problems (that they often get wrong anyway) and that costs them the opportunity to answer other, easier questions correctly. (In fact, I would argue that all careless mistakes are a result of this. You were rushing or mentally fatigued for some reason and that reason was probably because you spent too much time and/or mental energy on a problem that was too hard someplace else.)
Read these two articles:
https://www.manhattanprep.com/gmat/blog ... -the-gmat/http://tinyurl.com/2ndlevelofgmatAre you doing that kind of thinking during the exam and that kind of analysis to learn from your practice problems? If not, what do you need to change in order to do these things?
I'd also do a deep data-analysis on your most recent MPrep practice test. You can use this article:
https://www.manhattanprep.com/gmat/blog ... ts-part-1/If you haven't already, you can also sign up for a free account on our Atlas learning platform—it includes videos and a spreadsheet you can use to analyze your exam. (I would do this even if you'd rather use the blog post I linked above, because Atlas has other useful free resources in it.)
Based on all of that (and it's going to take you a few hours!), figure out your strengths and weaknesses as well as any ideas you have for what you think the lowest hanging fruit is for you—the things that you can improve as quickly as possible.
Then come back here and tell us; we'll tell you whether we agree and advise you further. And we'll see how far that can get you by your first test date and go from there!