Sounds very much like a Lower Esophageal Sphincter (LES) problem. Do you have other Gastrointestinal symptoms:Reflux, Esophageal gas, Bowel trouble? Before or after around the time of the pain do you notice a need to relieve yourself?
Does this happen after you eat certain foods? Say 1 to 2 hours after eating
Do you have risk factors for heart disease?:
, shortness of breath
on exertion, pain in chest on exertion especially radiating pain
, slightly elevated white blood cell
count, elevated creatinine
phosphokinase (CPK).,C- reactive protein over 3.0.? Hear is a suggestion: If you are active and have access to a treadmill walk on it while monitoing your pulse regularly. If your pulse is abnormally high for what you are doing a heart problem is likely. Find your maximum heart rate
(220 - Your age) = Maximum Heart rate. If you are walking or jogging at an easy pace and your pulse is very high. A cardiovascular problem is likely.Surely you could have a cardiac problem but unless you have some indicators of real heart distress I would lean toward LES problem. The LES may pop open when it should not. Possibly even the beginnings of achalasia, a disorder in which the LES fails to open when food hits it. Your problem could be fixed by a diet change, elevating your bed, not eating too close to bed time or it could be worse.
I am puzzled by your choice to lay on your heart side instead of the other if you have pain on that side.
I must tell you one would need a lot more info. to determine the possibilities.
The short answer: Of course you should have it checked out!