I am a 40-year-old mother with a four year old and a one year old. We denied the testing on both my children. My youngest turned out to be Down's. We denied the testing because these were God's children, and He would help provide for them no matter the circumstances. I had wonderfully healthy pregnancies with both children. My one year old was not referred for Down's testing until her two month checkup. It was positive. I was ever so grateful to not have filled my pregnancy and birth with the overwhelming feelings that accompany such a diagnosis. She is still God's child and He still will help us provide for her. I will admit, though, it's a lot easier to talk the talk of faith than walk the walk of faith. However, when you really need the faith, you don't have any other choice but to have faith. God always delivers on that faith. Parenthood alone is a walk of faith like none other, special needs child or not. I would never trade my pregnancy or delivery or newborn period not knowing she has Down's for anything. She was very healthy, and we had no reason to freak out. I did my research when we knew what we were facing and fought hard to see to it she was getting the medical screenings she needed.
My doctor was wonderful about us not wanting the screening. His reply to our reasoning was, "God will reward you." He has. She's doing great under the circumstances. Yes, it still knocks the breath out of me occasionally, but I turned her conception and birth over to God from the beginning. To waller in grief is selling Him and her short. I have no idea what her limitations will be and pray I fulfill her potentials.
If you don't want the test, don't do it. It's too inconclusive and amnio poses such a risk, I don't feel it's worth it. No matter what, it's a ride of faith.
Congratulations on your pregnancy! Enjoy it all to the fullest and let God fill in the blanks.