I Have Perirectal Abscess Which Was Drained 12 Days Ago.

I have perirectal abscess which was drained 12 days ago. I have completed my antibiotic dose prescribed by colon and rectal surgeon. I still have moderate pain and feeling uncomfortable while sitting and walking due to pain. Drained area is healing well as I am getting little pus discharge now as compare then last week. My only concern if it is healing then why I am getting pain that I have to take pain killer. For how many days I am going get this pain or it takes to heal completely?