M.H.
I had this when I was 12 weeks pregnant with my first child. I was told that the fluid measurement was high and that my chances of Down's Syndrome were increased due to this measurement. The fact that the baby has a nasal bone is a very good sign.
Please, please, please do not worry about this. These measurements, and the information they give you from the measurements, are not always accurate. They are based on statistics, but we are all different and all grow differently.
My son was born perfectly healthy after a lot of worry through my pregnancy. Just try to enjoy your pregnancy, it should be a wonderful time for you :)