abscess tooth infection swelling of jaw

Hello- I have a abscess tooth in my back molar that I will be getting a root canal on but I have to be on antibiotics for a week... My question is does the infection swell up and down while it is being cleared? It is the size of a baseball in my right jawline underneath my chin and it keeps going up and down and the pain is unbearable. Thank you in advance for your response.

[Jerome Tsang, DDS]

Maybe your dentist should start the root canal immediately and leave it open to drain out instead of closing it up with a temporary filling after the initial procedure.  

The antibiotics should help but it should have cleared up now after a week.