My stomach is beating like my heart. i can feel it when i lay down and i am not thin. i have alot of gas, no pain whatsoever. this worries me alot.

Aortic pulse: All arteries in your body pump to the rhythm of your heart. The aorta, the largest one,runs deep in the chest from the heart to the legs. It's likely this pulse you're feeling. Usually more noticeable in thinner individuals, but can be noticed in anyone. In older people (50-60 years), it may be a sign of aortic aneurism, but it best to get a proper medical evaluation to know for sure.

Possible hernia: You could have hiatal hernia. This is a condition where your stomach is virtually in your chest. You should see your doctor.