Question on blood test

I've seen a lot of people say that they got call backs on their genetic testing and ended up being told the gender as well...is that something that you have to specifically ask for or is it included in the genetic blood testing? I had my blood drawn yesterday for genetic testing after our NT scan and Doctor said it will take a few days to get the results back. Will they be able to tell me the gender or is that something that has to be asked for specifically and tested for specifically?