The cause for these new symptom of yours may indeed be very hard to pinpoint. Your first consideration about uneven nusing is a plausible explanation since milk can really make the breast engorge.
If your recent mammograms are normal, then it is unlikely that the breast cancer is causing this, especially in the absence of other symptoms such as pain, or lump formation. Just be sure to report any other abnormalities to your cancer doctor.
Regards and God bless.
I am sorry I should have clarified. My youngest child is 11 so it has been quite some time since nursing. Although they were always a little different since nursing 10 years ago, lately it has been quite significant. I have not begun treatment yet as we are still trying to find out how extensive everything is. All I have had was the excisional biopsy without clean margins. I had a MRI and BRCA last week and am getting ultrsound this week based on the MRI findings. It looks like there are other quadrants involved. My diagnosis date was 6/24/08. I know I am having more surgery, just not sure when or how extensive yet. All the info is not in yet