3.5 Nt

I had my 13 week ultra sound and am a mess. Had first ultra sound too early but they did the blood work to identify its a boy and no risk with my chromosome blood work
Now at a week and a half later there is high risk in my blood work and the thickness of his neck is 3.5 mm. 
Has anyone had this and go on to have a normal baby? I'm so worried for him. 
Next step is to see a genetic counselor. Neither of our families have any Down syndrome.