B.B.
Sigh. I'm always amazed, at these questions. I do not mean to sound condescending, at all. (I'm certainly not trying to be!) With all the medical technology out there...if these tests actually were effective...do you think they'd need expensive to buy, care for, and replace machines like the ultrasound? Don't you think they'd rather give a person a simple urine test and send them on their way? I think so. I worked with insurance and they don't make much money charging insurance, for ultrasounds.
You might be interested to know, that they are a part of a class action law-suit and are being investigated.You might end up having a boy...but you had a 50% chance anyway...which is pretty great odds. No, I don't think these tests should be treated as a scientific test. These tests are as good as a coin flip.