White spot on one nipple

[MrsFabuloso]

I have had a white spot on my right nipple since I had a bout of mastitis a few months back. It changes in size, sometimes only the size of a pinpr!ck, sometimes the size of a matchhead and in between. I have tried to squeeze it out, though I'm worried about hurting my nipple. Is it a blocked duct? Sometimes it starts to...well not hurt, but I can feel when DS feeds and it is pulling inside, like it's pulling the duct inside my breast. So I think the duct is still draining, there is no lump there or anything. That was the feeling I got when I had mastitis too, though it was painful then. I'm worried it is going to cause another bout of mastitis. What should I do?