Down syndrome risk

Autumn • mama to one little boy 10.09.2017 and one little girl 12.7.2020
My doctor just called me and told me that our testing came back high risk for Down syndrome. She said 1:270 is what they consider low risk, and ours came in at 1:260. I have to go get another ultrasound and more blood work done, as well as genetic counseling. I am absolutely terrified. Has anyone experience this? What was your outcome?