About 8 months ago, I realize one of my nipples was partially 'collapsed'. After some time it has gone completely inverted. At first, I thought since I had my daughter in April of lat year, perhaps it was a milk duct issue. It has now been 8 months, there is no pain, no discharge. When I try to squeeze to push it back out, it inverts even more. I am 32 years old, and its been 3 years since my last mamogram. Should I be concerned about this??