Ask a question...I have pain on my left breast

The lump could be a result of the injury to your breast.  Your use of the word "severe" to describe the pain makes me think you should call the doctor today.  The nurse on call can assess your situation and see if you need to be checked out immediately or if you can wait and see what happens.

If this pain, burning sensation and swelling in your nipple are a result of the knock to your breast, they will start to get better in a day or two.  If they don't get better, they could be symptoms of an infection or a rare type of cancer called inflammatory breast cancer.  If you don't see an improvement within a week, be sure that you follow up with an appointment with a doctor.