At the pregnancy expo I bought a foam pillow designed to prevent deformed heads when baby likes on its back in the cot. It's like a small square with a contoured hole in the middle that cradles the baby's head. When I saw the early childhood nurse she said don't use it because the baby will turn its head around anyway, and it's a SIDS risk. I feel like I've wasted my money now because I am too scared to use it. Has anyone had success with this type of pillow? They say to use it up to 4 months.