 2. Enrolled patients will then be screened for bacterial vaginosis at their next visit typically on menstrual cycle day 12, prior to transvaginal ultrasound. The screening will require that a speculum be inserted into the vagina and a vaginal smear be collected with a swab from the posterior fornix. A microscopic slide will be prepared by rolling the swab on the surface of a glass slide. The diagnosis of bacterial vaginosis will be established clinically using the Amsel criteria to confirm 3 of the following 4 signs: clue cells; vaginal pH 4.5; fishy odor before or after the addition of 10 potassium hydroxide solution to a wet-mount side; and a homogeneous, off-white, discharge. For validation of clinical diagnosis, 100 of screen positive slides, and 10 of screen negative slides, will be sent for to the Department of Pathology for Gram staining. 