Well first, congratulations on your NEGATIVE results. I hope you feel more relieved with them.
I have to say, I'm surprised that you wrote that now they can determine the gender from this test. As you may (or not) recall, I had the MaterniT21 test not too long ago. We had asked our GC if the babys gender would be able to be determined and were told no. Since we also had to call Sequenom about a few things, I asked the question directly to them, and was told no way. In fact, I was also transfered to their lab and they unequivocally told me absolutely not. They said while the technology is there, they do not use it, as it's too new and there is still significant FDA oversight due to the novelty of this test for anything other than detecting Trisomies 13 and 18 and DS.
In any case, congrats on team blue
Your numbers were great. It's pretty uncommon to get a negative MaterniT21 test and then have a DS baby but you have to do what's right for you as far as deciding to do an amnio. Good luck.