Is it pain or soreness. If its soreness than its normal but if its major pain I suggest going to your doc
Brown discharge is ok. You should only be concerned if it turns to red. As far as the breast pain, I would definitely check in with your doc. You should expect soreness, but it sounds like something else to me. Good luck!
I'm on my 4th pregancy and have had sharp pains radomly with each one. My doctor told me its just growing pains. But if your worried then ask your Dr.