thank you for your query.
first of all it is good that you started anti-biotics after the dog bite.it is very essential to prevent any further infection.but it seems like in the few days some bacteria have entered the skin causing infection.hence what you are experiencing is mostly an abscess
It is good that you drained the blood and pus out already.hence,what remains is completing the course of anti-biotics and keeping the wound clean.
*use anti-septic agents to clean the would
*keep the area clean and dry
*you can do hot compresses to facilitate the draining of the fluid
*keep the area mobile but not excessively
by following the above your lump should clear up in two weeks.
wishing you good health