My 4 month old just started pulling off my left breast after few minutes sucking on it. I know she is not finished because the breast still seems full and she is not happy so I put her on another breast. This has been going on for a few days now. Can I have a plugged duct? I am afraid this will give me mastitis so I pump the breast when I can but not after each feeding. I read it could be anything - milk for too fast or too slow, etc. but that doesn't help me figure out what's up (I have had low supply issues for some time now but she pulls off even when I have enough milk).