What Causes Swelling In Breasts After 6 Months Of Delivery?

I have a weird question, i guess. I had my last child 6 months ago. My breast went back down to size within weeks after the baby. I have had no problem at all. Now all of a sudden I keep getting that feeling in my breast like they are filling up again. I get that feeling 2 or 3 times a day. I have been feeling sick here and there and i have been getting restless legs alot at night. Right now I feel dizzy and sick. I have been having some pregnancy symptoms again.. but.. I am on my monthly now and have not missed a period. They do not come at the same time every month and are light. And I have been on the nuvarang for months now. Could it be the birth control making have these symptoms or what could it be?