Another person posted on Inspire.com who is having bloody discharge too last night. Damn!
You should definitely go get it looked at. I'm thinking that the imaging needs to include diagnostic ultrasound but the newer developing standard is for a diagnostic MRI. Can you get one?
There are other conditions such as papillomas that can cause bleeding so the jury is still out but you are rightfully upset and concerned about this development.
Here's the article I found:
Breast MRI in Patients with Unilateral Bloody and Serous-Bloody Nipple Discharge: A Comparison with Galactography
http://www.hindawi.com/journals/bmri/2015/806368/
Keep us posted.