Kay, it's more likely to be a cyst or some problem other than cancer.  Most breast cancer lumps don't hurt.  However, pain and tenderness may indicate a problem that needs to be checked out by the doctor.  If this pain has lasted longer than a menstrual period or if it is accompanied by fever, redness, or swelling, then you need to call the doctor and get it checked out.  Pain--along with redness, swelling, and skin dimpling--can be a symptom of a type of breast cancer called inflammatory breast cancer (IBC).  It could also be an infection.  Sometimes breasts just hurt and no cause is ever found, so the chances are this is not something serious.