Thanks for asking the query,
The swelling which appeared is known as Hematoma
, it is painless distended swelling .
It occurs due to effusion of blood into the extravascular spaces during the injection of the local anesthetic
Immediate management of hematoma is application of external pressure over the affected area .
It can be relieved by application of ice packs on the affected area.
Take complete course of antibiotic and analgesic
Usually it takes 7-14 days to resolve .
Hope this helps out .