I was treated for an abscess tooth today. Had mild facial swelling on right side of face, but is getting worse. Is this normal?

It can. It can get worse before getting better. Usually you need antibiotics for an abscess and it can take 24 to48 hours to, work.
Antibiotic,steroid. Control the swelling and the infection then you will not have the pain. Infection is controlled by the antibiotic (clindamycin) before and after the root canal treatment. Swelling is controlled with steroidal therapy such as Medrol (methylprednisolone) dose pak or NSAID (ibuprofen, motrin, advil) which reduce the swelling and therefore reduce the pain.
What treatment? Were you given antibiotics? Any other treatment indicated? Too many questions left unanswered.. Please call your dentist.