Hi! Good evening. I am Dr Shareef answering your query. Although it needs a physical examination of the lump, from your history, it seems to be an epigastric hernia, which is protrusion of a small amount of preperitoneal fat through a week point in the liniea alba, which might have been caused by the stretching during your last pregnancy. This herniation could give rise to the lump along with the dull achy pain in your case. The treatment of this conditoin would be a small surgery. However, this has to be examined physically by a general surgeon who would then decide on the course of action and proceed accordingly. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic to clear doubts on your health problems. I wish you an early recovery. Dr Shareef.