How To Treat Greenish Black Discharge From Nipples Due To Overactive Milk Duct?

Hi I have had a greenish black discharge from both nipples for about 3 months my doctor put me on antibiotics which didnt help and I have had a mammogram and a ultrasound which showed no problems just lots of cysts but I still have the discharge. Last time this happened I was told it was an overactive milk duct and it was operated on. My current doctor said not too worry about it, but it is embarrassing when I am with my husband and I want it to stop should I ask to see a specialist? I am 47 and not breast feeding not pregnant