Have an abscess tooth, on day 3 of antibiotic and yesterday my lymph node started to hurt on that side really bad but gums seem to be doing better.?

See yr dentist ASAP. The most common cause for toothache are inflammations and not infections. Antibiotics are rarely required and should only be used as an adjunct to dental treatment for infection since they may complicate further outcome. Take the NSAID OTC or Tylenol (acetaminophen) to control pain and see your dentist ASAP.
See dentist. Sounds like the infection may be spreading to the lymph nodes. Contact the prescribing dentist today to discuss.