Breast pain, a very faint burning sensation!

I last had my period around March 9th, and it was regular. A week ago I thought I had found a lump in my one breast. I called and made an appt with a doctor for an examination, but it is not for another week and a half. The past few days both of my breasts have been hurting, as well as my armpits every once in a while. It's almost a very faint burning sensation. I have been on birth control for a few years. What could this mean? I research and see a lot of pregnancy signs. But I take birth control regularly and use a condom every time. Thanks.