Why is the right side of my jaw hurt and swollen?

Swollen jaw: i cannot tell you why your jaw is swollen, only a dental exam can answer this. But you may have an infection, abscessed tooth, salivary gland problem, jaw injury or other things. See a dentist ASAP

Dental infection: Unless you have sustained injury, the most likely cause is infected tooth. other things like tumors possible. See your dentist or oral surgeon for diagnosis and treatment.