Concerns After Ultra Sound

I am 24 weeks pregnant and just went for a follow up ultrasound, I went at 18 weeks and was told that I was going to have a boy, but his hand was in the way to see all four

chambers of the heart. I went yesterday for the follow up this time the tech still could not see all 4 chambers, The baby is growing and moving alot. She told me I would need a

Level 2 Ultrasound. I am scared to death. Can a baby live without all 4 chambers.

Everyone is telling me not to worry but it is hard to do with somthing growing inside you that you get more attached to each day.