I developed tenderness in the nipple of my left breast about 4 months ago. It lasted about 2 weeks and then went away. However, I scheduled an appointment with my gynecologist who checked for a lump and reviewed the results of my recent mammogram. All was fine. Now the tenderness is present, once again. It is not as pronounced as last time, but I definitely felt sensitivity this morning . I plan to call my gynecologist on Monday, but am concerned.