CassyTanya,
I have twin girls, fraternal, who both have salt wasting CAH. Of course, being girls, we knew at birth due to their ambiguous genitalia. After you get things sorted out with your son, you might want to at least ask the endo about testing your daughter. One of my girls weighed around 22-23 pounds at 8 months. Now they are 20 months and weight 20 and 30 pounds.
I would definitely call the endo and keep calling until you get answers. Or ask what the holdup is. A week is about standard for getting results back I think. Please let us know what you find out.
Cassy