This study will compare two investigational techniques for measuring how vaginal gels spread and coat the vagina. This study will also explore the experiences and opinions of women using this vaginal gel. We want to understand how the characteristics of a gel, such as a gel's thickness or consistency, affect how the gel spreads and feels in the body. We hope to use the information we learn from this study to develop future vaginal gels that could be combined with medications and used to slow down or stop the spread of sexually transmitted infections.