Pus with retired nipple piercing/breastfeeding

I had one of my nipples pierced two years ago and removed it almost a year ago. Ever since there is a small amount of white pus that can be squeezed out like a pimple, but only on one side because the other side of the piercing is closed. I'm going to, of course, ask my doctor at our next visit but was wondering if any one has had this problem and if it affected breastfeeding.