Downsyndrome?

Has anyone been told the fluid on the neck at 21weeks measured slightly more then it should and it could possiblly be downs... but heart and brain and other organs were growing just fine. My doctor is sending me to a specilicist to get him to see if it really is or not but its a little scary. If he is it wouldnt bother me but its still netve racking. So im just wondering if someone else was told this and how it turned out?