it is extremely rare for salivary gland
to get such noticeable swelling in a time frame of 2 or 3 days. More commonly it can be enlarged SUB MENTAL/ SUBMANDIBULAR group of lymph nodes, which are found at the, location as you have described in your case. the incidental swelling of lymph node is common in cold sore
or any other oral infection. Keep a good oral hygeine with twice a day gargle with Chlorhexidine
mouthwas, it should resolve within a day or two.
alternatively you can also take amoxicillin
antibiotics- 500 mg twice a day for 3 days.