 Participants assigned to IVR do not have to be sexually active with a male partner. IVR assigned participants will use a total of 3 IVRs, one at a time. IVR assigned participants will use the first IVR IVR1 for approximately 24 - 36 hours no exposure to semen during IVR1 use. IVR assigned participants will use a second IVR IVR2 for approximately 7 - 10 days and a third IVR IVR3 for approximately 28 - 32 days. During the use of IVR2 and IVR3, participants may engage in sexual intercourse, but it is not required. Women assigned to IVR use will be seen over 5 visits. 