I have had the amnio (my choice), with both my pregnancies (both my kids are fine), and I am glad I did. I had my testing because I was 35+ years old, with each pregnancy.
The test sounds scarier than it actually is. It does not hurt more than a bad menstrual cramp. They do "numb" the area prior to the procedure.
Shani W. is correct. An Amnio does not cause miscarriage as much as people think....The percentage of it happening is not high. And certainly, only have it done by a qualified experienced Doctor. My Doctor did mine... and the entire procedure was over before I knew it. It was not sore or traumatic. My Husband accompanied me and I just held his hand during the procedure. They even have a video monitor up so you can 'see' it. My Husband said it was neat to watch.... but I was too much of a wimp to watch it myself. :)
The amnio will be the most conclusive. I am glad I had it done... because know I know for certain, that my children do not have any genetic concerns.
My cousin, when at your friends age, had a baby, with Down's. They knew about it before his wife gave birth. His son is now about 3 years old... and he was/is the most cutest/adorable/happy/blissful baby ever. Their lives have not changed negatively, and in fact, they are blessed by it. He is a very loved child. In fact, they routinely have their son in Theatrical plays with them, which they produce. (my cousin is an actor), and their son LOVES it. It is great fun and educational for him. So, you see, a Down's child is not anything "bad"... but there may be a mental-block about it from others.
Either way, I am an pro-amnio Mom. It was not a bad experience for me. In fact, before my 2 children were born, I did have a prior miscarriage... but I still went ahead and had the Amnio testing, with my subsequent pregnancies. It is safe.
With my daughter, during the Ultrasound, they thought something was "wrong" with her too as there was an anomaly with her heart. I had the Amnio after that. My choice. It was then found that NOTHING was wrong with her. Thankfully.
Either way though, I would have had my baby... who is now almost 7 years old.
All the best, just some personal experience,
Susan