OP, I assume that you only had the blood test? I think you have to look at what the test really is. It's statisitcal analysis of risk and no more. You get a result of level X of factor y in the blood and based on your age and other things we come up with result Z. It's really like a pre-screening to say maybe you should get further (amnio or CVS) testing. How old are you? That alone increases the risk of having a Downs baby. The reason that amnio is suggested after 35 is that the risk from miscarriage (1 in 300/350(?)) is the same has the risk of having a baby with Downs.
I am 39. I talked to my OB about what pre-natal screening I might want. He said based on my age alone to SKIP the quad test because it would come back as high risk of Downs. If I was really interested in the result, I should go to the definitive test.
My point is that quad test is not a great indicator of outcome but of risk of outcome. IT also has a lot of false positives (results that are NOT going to occur).
Talk to your doc about whether they suggest more testing or not. I also agree with the poster who said 95% is some good odds!