Hi Schachfreizeit.
To get to 650, you'll need to increase your quant score substantially and your verbal score by a few points.
You may be able to do so in four weeks, but your current plan for quant doesn't look strong enough. In doing just OG quant questions and doing questions in the order in which they appear in the OG, you won't be focusing on one topic at a time, and thus you won't be learning as efficiently as you could be, or as you need to be in order to get to 650 within four weeks.
So, my suggestion is that, rather than just do OG questions in the order in which they appear in the book, you work in a more topic focused way.
You could do so in a few ways. One is that, if you miss an OG question, you then focus on that topic by learning concepts and strategies involved in that topic and then answering dozens of questions involving that same topic until you're getting them correct consistently. Another would be to assume that, since you're currently at Q38, you need to learn most quant topics and skip the step of waiting until you miss a question in a topic and, for each topic, simply learn the concepts and strategies and practice.
Also, 10 questions a day is not a lot. In verbal, 10 questions a day could make sense. However, in quant, if you're focusing on one topic, you could do more than 10 questions in a day. You don't need to do 50, but you could do 15 or more, even if you're doing them untimed, and on a weekend day, you could do dozens.
For some tips on preparing for GMAT quant effectively, see this post.
How to Increase Your GMAT Quant Score: Top 25 TipsAlso, it would be good to read this one to learn how to practice for the GMAT for best results.
The Best GMAT Practice Methods