Genetic testing. Sad news

So I'm 14 weeks tomorrow. I had my genetic testing done at 11 weeks for CF, SMA, fragile X and they tested for gender. I was hoping to find out what were having.  Instead I got a call yesterday the dr wanted to see me first thing in the am.
I was told today the results said our baby has only one X chromosome. It's a girl with Turner syndrome.  I'm hoping it's a false negative. I chose to schedule an amniocentesis to check the baby's blood and be sure.
So scared. Anyone have this happen to them? Know anything about Turners. Ever have a false positive?