So I am on birth control (the Nuvaring to be specific) and have been for about 9 months. I only have sex with my boyfriend and he always wears a condom, and we have never had one break. Prior to going on birth control I didn't have bad PMS but I did have tender breasts.

My last period started Wednesday January 21 and ended Monday January 26. This is pretty much exactly how my periods have been since I've been on birth control. This one was slightly heavier than it had been the last 2 months, but nothing alarming. About two weeks prior to this period starting I started feeling depressed and my right breast was tender. I was concerned I might be pregnant and the day before my period I took a home pregnancy test, the test came back negative and then to confirm it my period began the next day. When I took out the nuvaring I noticed that my breasts were not tender any more and had no tenderness the week of my period. Then I put a new ring in Sunday January 25 as directed. Beginning Wednesday January 28 i once again noticed breast tenderness, this time in both breasts.

I have done a self-breast examination and have noticed nothing unusual. Why would my breasts be feeling tender?