As you said your haemoglobin is on lower side that may lead to high output state for heart that means heart needs to pump rigeous than normal to combat low haemoglobin in blood. This may be felt as pounding heart by the pt. When she/ he lies on left side where heart comes nearer to the chest
Next Steps
Needs cardiologist consultation once and 2D Echo to be done
Health Tips
East more of fruits vegetables, dry fruits, jaggery etc. to combat your low haemoglobin along with iron tablets or syp. as supplements