Genetic testing

So I dud intial blood work with a MS specialist and results came back....in the words of dr. Ypur results were positive and high for down syndrome. My understanding its just a screening and can be a false positive. She stated 4%chance 96% my baby is fine. 1 out of 23 women with that percent....any one else experience this scare/stress! Or hv thoughts about results. I'm 12 wks 1 day. Thanks!!!