<qa>  What is the name of the swab that will be collected from the posterior for2. 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. 