Bleeding Nipple

so I had my mammogram in December everything fine. Then about 3 weeks ago I started getting shooting pains in right breast so bad it would wake me up at night so the dr sent me for a ultrasound which showed 3 tiny simple cysts no further treatment needed. So that was that then Tuesday after my shower my right nipple started bleeding , it wasn’t a discharge but bright red blood. It stopped as quickly as it started and haven’t had any more bleeding. The dr was concerned so I’m booked in to have a mammogram on Monday and a ductagram on Wednesday the only thing is to have the ductagram you have to have active bleeding or discharge or it cannot be done . Has anyone had this nipple bleeding that happened just the once, what was the outcome ? Thanks in advance