Pregnancy, lol. It'll make your everything going hurt. Hormone surges can cause shooting pain. Your breasts are going to grow a bit which can cause pain.

growing more than likely. after a month of me being pregnant my boobs have not stopped growing and i had same thing. i was a 38ddd and now im a 40 f maybe not sure because my bra is starting to feel tight again lol but if you have any concerns bring it up to doctor when you go.