Hi! Good evening. i am Dr Shareef answering your query. From your history it seems either to be a starting point for a left sided inguinal hernia or to a muscular strain following some heavy work or sudden stretch. To know exactly what it is, you need a physical examination of your abdomen to be conducted either by your family physician or a general surgeon. Till then you could go for an anti inflammatory drug for a symptomatic relief. 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.