Throat will be painful because of Infection of tonsil and associated inflammation which has spread to surrounding areas.
Response to Antibiotics and anti inflammatory drugs in Tonsillitis
depends on its severity.Higher antibiotic with broad spectrum of action can be useful,but to be used cautiously in pregnancy
Though you are pregnant,you can go for Tonsillectomy
surgery ,if the symptoms are severe.
Please consult your ENT surgeon and take decision.