💗💙 Gender reveal by blood test ⁉️

I had an appointment today and the doctor I can get a genetics test (I think that’s what she said it’s called). It tests for Down syndrome and things like that, but she says a lot of women get it because it can tell the gender of the baby. So of course I agreed to get it for that reason as well ! But my question is how accurate is it ? Anyone ever had it done and it say you’re having a girl but it’s actually ends up being a boy or vice versa ? I go take it Friday along with the glucose test ... yaaaaaay (definitely sarcasm there! 😂)