Yes this is normal. I use both breasts to feed, however my babies both have always preferred my right breast due to the shape of my nipple. So at times it is obviously the bigger breast, and I also know I produce more milk from that breast. After I finished breast feeding my first baby, and my milk was gone, I did notice that there was still a difference in size. Also, one side of your body is smaller than the other, regardless of breastfeeding. So that could be part of it too.
That is how mine breasts are, only my left is bigger than my right because that was the side all three nursed on. I plan on getting breast augmentation to even mine out sometime in 2009. There is a good 2 cup difference in my breasts before I nurse.
I don't know that there is a way to fix it without surgery. Perhaps time will even them out. I have never gone more than a few months without nursing or being pregnant in the last 7 years : ) That is why i am waiting until 2009 to move forward with the surgery.
There aren't many females whom have breasts that are the same size or shape. No worries. Heck I even had a breast reduction done, and one is still a little different then the other.
Thank u very much ,for the help.