Tests

Kayla
So I'm new to all of this, I'm only 5wks 3days, I have to have my first scan at 12 wks, MIL is telling hubby that I have to have some test around 11 Wks to see if the baby has Down syndrome or something? Is this true?? 
My doctor nor midwife person said anything about this??? And when I spoke to my mother she said she is certain it's only when your in your 30s or so that they do that test??? Can anyone help me out here??? 
Thank you