Pulse in my stomach worries me just started last night. i am 6'7 245 pounds. the pulse matches with heartbeat and i only feel when i lay down. ?

Aorta: You are likely feeling the normal pulse of your abdominal aorta(the main artery in your abdomen), more noticeable when you're laying down. This is common in relatively thin people especially when lying down, and you've probably just become aware of it. That said, you should still see your doctor to have a physical exam, especially checking your blood pressure. Hope that helps