I am a 44yr old woman, yesterday in the shower I thought I felt a hard lump situated on the bottom of my right breast right on the bone in cleavage. I do check my breasts regularly and had not felt this. The more I examined the more I can not decide if is the breast bone or a lump attached, seems stupid, surely I should know?? The more I examine the more painful it is, I am menstruating at the moment. I am worried over not much or should I be worried. Please help!!