i am 13 weeks post partum. last week i started weaning from breastfeeding and one morning , after not feeding for 12 hours, my 4 year old daughter ran up to me and hit me pretty hard on my left breast causing severe pain behind the nipple. Now i have achy pain behind the nipple all the time and everytime i hold my 13 weeks old it gets worse and lots more pain when the breast is pressed against . what could this be????? i am a 31 y/o female who has a history of graves, ra, and lupus. familial hx of hodgkins and colon ca.