My breasts have been sore for the last two weeks, but i'm not expecting my period for another two weeks. could i be pregnant?

Maybe you need to: check for pregnancy. If first test negative, then check again in 1 week. It is always good to assume that you may be pregnant, since breast tenderness is one of the first signs of pregnancy. If both tests are negative, and you have a period, then you know you are not pregnant. Breast tenderness can also come from hormonal imbalance and overstimulation, or infection if it is just one breast.