I just posted this same question! I then did research on it on the website. From what I could tell, if it is both breasts, then it is probably normal. Many women, who use to be nurses for the rich (they literally nursed), can still produce milk though not pregnant. Adopting moms can too. It has something to do with hormone levels, etc. Mine have now pretty much stopped leaking, but just recently. If it is only one breast, then that is cause for concern and should be seen by a doctor. If there are any other concerns, lumps, tenderness, pain, etc., then I wouldn't hesitate to call a doctor. You could anyway just to ease your own mind, because it could also be a tumor. I decided to wait it out due to my family history and that it was both breasts. (My grandmother would nurse for other moms when they couldn't.) And as I said, all seems to be ok so far.