I had my 2 at 33 and 35. Had such terrible sickness with both of them, I was so aware of the baby I was carrying, right from the very early stages. I choose not to have any additional testing for either, only the basic routine screening and scans.
I am now the mum of 2 wonderful childrenincluding my dd (3) who has Downs Syndrome. She is happy and healthy and to me, as bright as a button. I wouldn't have her any other way.
I have heard so many stories of babies with being born and only then being diagnosed, a good percentage of them also having heart defects. On the other hand I have also heard so many stories of "high risk" mothers being worried sick and considering a termination, only to find their baby being born NT!
I personally am glad I didn't know, yes, it was a shock when she was born, but mother nature had already kicked in and I still had a beautiful, wonderful, amazing little girl to care for and love to bits!
You need to decide for yourself about what you would do given any "negative" results of these tests. If your answer is nothing, then personally I wouldn't bother.
Congrats, and hugs, love Dingle.