Need help with milky discharge through nipples

Patient: I have a question regarding a problem my wife is facing currently. Couple of days back she observed that while she squeezed her breasts a white milky discharge happened through both her nipples. The discharge was salty in taste. This happened only when the breasts were squeezed. She is not pregnant.As a quick history, she is mother of two and she breastfed of the kids. Last childbirth was in December 2011. Recently she was on oral contraceptives for 3-4 months till June mid and then she stopped that.We are concerned about what could have caused this discharge. Request your help and assistance in the matter. We are yet to schedule an appointment with a gynaecologist but based on your guidance and advise would do so, if required.

Symptoms: White milky discharge through both nipples when squeezed