This is the website for the harmony test:
https://www.ariosadx.com/
I am having it because I am high risk for a large number of reasons. I believe if you are advanced maternal age, insurance covers the test in the US. It tests Down, Edward and Patau, as well as XY XX and I think can detect Turner. My OB says if the result is positive for boy, all results are 99% accurate. If the result is girl, 90%, because of the possibility they are catching your DNA rather than the baby's. It is a blood test on you, non-invasive. You can get a lack of result if you are exhibiting low fetal DNA in your bloodstream, but that is usually if they test too early. My perinatologist won't perform the test until you reach 12 weeks. I'll be 12 weeks tomorrow, when I get my test.
I am also doing the NT and triple screen tomorrow.