if it dont fizz it means a girl and if it does fizz its a boy. i tried this in the early pregnancy and it fizzed and then when i did it in the second trimester it didnt fizz and it was indeed a girl=) that i am carring. i found a website that said this, this method was used by several members to test the accuracy of their gender ultrasound and out of 31 baking soda tests, 22 were right and 9 were wrong=) and thats what i found=).
I'm pretty sure it's just a matter of how acidic your urine is. Mine is always pretty acidic, so the baking soda test says i'm having a boy. Nope, we're definitely having another girl.
I think that means that you are all pregnant with boys! Lol! :D