Many people are larger on one side than another.  If you are right-handed, some of that difference could be from the muscles that are under the breast from more use.  If you have had this difference since you finished puberty, there is nothing to worry about.  And the small bumps are perfectly normal too.  The next time you see a doctor, you might mention the size difference so that it can be noted on your chart.  If you have recently experienced a change in size, you need to go ahead and check with your doctor.  Swelling--especially if accompanied by pain, itching, and/or redness--could be an early sign of inflammatory breast cancer.   Increased breast size and changes in nipples can also be an early sign of pregnancy, but that would usually happen on both sides.  I commend you for paying attention to your health.