I am having pain in my stomach at the bottom it's a knot. i have a knot on the left side of my stomach under my brest. what does it mean or what i ne?

Any knot needs exam: There may be a variety of reasons for pain or tenderness with a knot. A superficial knot may be as minor as a muscle spasm or something more serious such as an abdominal wall hernia. Inflammation of internal organs could also cause pain and swelling. This would be much more serious. It would be much safer to have a physician examine you to determine the exact location and quality of the pain.