This sounds like an infection.
Pain, redness, swelling, and purulent drainage all are signs/symptoms of an infection. Fever and chills come next, followed by more serious issues. You should contact your surgeon urgently. Do not take antibiotics you may have "left over" from some other treatment or from your surgery, as different antibiotic coverage may be required to eradicate any infectious bacteria, and may also require opening up your incision to drain any abscess collection.
Call your surgeon's office now; do not...