What Does Blood Discharge From Breast Post Injury Suggest?

I am 60 years old and a very active, healthy woman. Recently (30 days), I received a hard blow to my right breast by a horse when he knocked my into a stall door. I was slightly sore, but everything seemed fine after a couple of days. Now, however, I have noticed that breast has a dark, red blood that comes from the nipple if pressed. There is no pain or discomfort, swellings, redness, tenderness or anything that looks unusual in that area. Any ideas?