It is not unusual for one breast to be larger than the other. It is unusual for one breast to be this much larger and for the change to occur rather suddenly. You should have a complete breast exam to make certain that a cyst has not developed.

The fact that you have a discharge from this breast is not normal. I am assuming from your description, and because it is common, that your discharge is breast milk. This condition is known as galactorrhea. If this is the case, it is important that you see your physician and have a thyroid stimulating hormone (TSH) test and your prolactin level checked. These tests will help determine the cause of the discharge. Most likely these tests will be normal and the problem will resolve. However, it is important that you be evaluated.