I took 7 days of antibiotic for cellulitis in my finger 2 weeks ago. It is still swollen, purple and puss is now coming out. What now?

See your doc. I recommend going to see a doctor to make sure the infection isn't worsening.
Infection. Could also be something known as a "felon." felons are closed-space infections of the fingertip pulp.
See MD again. Go back and see your doctor again. It's not cured. Get a culture done. You might need a different antibiotic. You might need an x-ray to evaluate for bone infection/osteomyelitis.