I have a small hard knot near my nipple. plus my breast are very sore and tender to the touch. also they feel fuller, and heavier. but are bigger too.

Hormones?: You should be checked by a physician. The "knot" could be a result of tissue stimulation by a hormonal imbalance. This would also go along with your breast symptoms. This can also occur at certain times of your menstral cycle. That being said, it could also be an infection, or breast cancer. Not to scare you, but you really should have it checked by a physician.