When should I take the Gmat Prep tests

Your test is pretty close - you should definitely start taking the tests ASAP!
One element of taking tests, just as Mohater said is to understand where you are and what you are missing.

If you have not taken GMAT Prep - definitely take it (download GMATprep) - it will give you a pretty close idea about your final score. Also, you can use https://gmatclub.com/gmat-score-estimate/ to understand where you are.

Depending on what you find out, you may want to consider rescheduling. I am concerned that you are too close to your date and have not done much full-test practice (including AWA).

Not taking any full length test till now was a mistake - I agree. I cant go back, but I can surely use the test as a critique of my performance. I share your concern BB and I think I will postpone my GMAT atleast by a couple of weeks and see how I do on the tests.
I read through your approach on the GMAT verbal section: I kind of like the idea of attacking the questions (even the SC's where you prephrased your response based on the error you recognized).

I need to practice, practice and practice for the next couple of weeks - but I think I may not have enough material. I have 6 MGMAT tests+ 1 Gmatprep left(well 3 if I re-install after completing the 2nd test) + 2 powerpreps/gmatpreps(that have been uploaded on this site). I think I may as well buy the 6 tests compiled by the site-members. Any other material you want to suggest?

I have a question-should I do the entire tests or skip the AWA and go directly to the Quant section? I know it wouldnt be very accurate as my brain might not be as fresh on the exam day as it would be during the test condition - but still I would be able to chew down a lot more sections that way. For the first Test I did do the AWA and I dint have much problem. What are your thoughts guys?

Ideally you want to do AWA's but many skip them. It is an extra hour, which is quite a bit of time. I'd say you definitely want to do the couple last tests with AWA's. The first ones may not be as critical, but AWA allows you to get the full feel for what energy and endurance are needed for the test.

That's fair! BB - could you suggest some practice material - in addition to what I have mentioned in my previous post?
Thanks!

Should be enough. If you run out, you can find others here: all-gmat-cat-practice-tests-links-prices-reviews-77460.html