Swollen gums are common in pregnancy. Better to consult  a dentist and have a scaling done. If the infection  is severe he may check with a radiograph and plan treatment accordingly.

Professional Scaling and polishing followed by home remedies are better cure. Swollen gums are sign of inflammation which is the first sign of infection. Why wait till the end and get an invasive treatment when you can simply get a cleaning done and it might just reverse the state . If still persist it needs followup. Otherwise general cleaning very 6months should be the future protocol.