Patients will be recruited around the time of their routine obstetrical visits. They will be asked to participate in three visits total. Visit one/enrollment occurs between 16 and 20 weeks of gestation, visit two at 20-24 weeks, and visit three at 24-28 weeks. At each visit, vaginal swabs will be collected. The patient will also be asked to fill out a series of surveys related to stress, anxiety,and depression in pregnancy. Research coordinators will perform chart abstraction after delivery.