Why am i getting a swollen tonsill if i'm already on a antibiotic for a tooth abcess?

Different bacteria ?: The antibiotic you are taking for your abscess may have no effect on the bacteria affecting your tonsils. See your physician to determine the cause of the swelling.

Solution needed: Antibiotic treatment helps reduce the infection from an abscess, but does not solve the problem. You will need either a root canal procedure to remove the infection or extraction to remove the infection. Until the infection is completely resolved, you may still have a swollen gland. Do not delay in getting this solved ! good luck.

Viral infection: If you have viral tonsillitis, antibiotics will not help. The condition will run its course in 1-2 weeks. If concerned see your PCP for evaluation..