I remember with Jack they told us that one leg was a lot longer than the other and that when he was older he may have a limp!! He has two totally normal legs!! I take their measurements with a grain salt, it's amazing how different each sonographer can measure the same baby, it's all just the click of a mouse hun.

As for laying on your back.....when I went for my last U/S, I had to roll over onto my side because I went all clammy and almost passed out. When you are preggers and lay on your back the baby puts pressure on a main artery that goes from your legs up to your heart.