HELP!!!

Monica
So as of today I am 19 weeks. About 2 weeks ago I went to my dr appt and dr asked if I wanted the genetic blood screen and of course I said yes. My husband and I always agree so we can get an idea and be prepared for what's ahead. Thankfully I have had 4 healthy pregnancies. This is my 6th pregnancy but when I was pregnant with my 3rd child, at 21weeks he was stillborn due to umbilical cord wrapped around his tiny neck twice. So we know that was due to natural causes. And ever since this I have been considered high risk and always get ultrasounds done to make sure everything is okay. 
But as of yesterday I received a call from a nurse at my drs office and she told me that I had high blood levels on the genetic testing and that I would be getting a high risk ultrasound, which I already knew I was, but she said the specialist would be looking into more and that I would be told more there. I tried asking questions like what does it mean?, is there a name to what is going on?, what all can you tell me,? None of my questions were answered and she said I would be told more at the ultrasound. 
I'm just curious, has anyone else been told this before and if so, what does it mean?