NIPT harmony test

So my Dr spoke to me several pregnancies ago about me getting this and I’m considered it but this pregnancy has really made me want to, can I ask if anyone els has? Is it just a blood test? Or do they do an ultra sound as well? I’ve been doing some reading on it but would love to get more first hand experience info. If you choose NOT to do it after your dr suggested it why?

Just trying to make up my mind (the money isn’t an issue for me) more the other aspects :) Thankyou