These tests are not 100% accurate. Had a young lady in our church who was told her unborn child would have DS. She carried it to term and had a perfectly normal baby...no DS.
I was told to abort my last child by three doctors. I was taking a medication (Methotrexate) that causes birth defects (mainly Spina bifida & miscarriage). Also they didn't know how the pregnancy would affect my disease and if I would have another stroke or not. I told them no. I was then told to at least go see a genetic counselor. I saw the genetic counselor and they said that they couldn't tell me if I had stopped taking the medication soon enough and left it up to me to decide. I told them no again, that I would not abort.
My daughter is perfectly heathy, normal and smarter than a whip. Can you imagine if I had just aborted? Because frankly, it would have been a lot easier on me (physically and mentally). Good thing I'm not LeftyMom, my daughter wouldn't be here today.