To assist women in monitoring their cycles, the provider gave them CycleBeads® a mnemonic device, a string of 32 beads in which each beads represents a day of the menstrual cycle. The first bead is red, representing the first day of menses; the next 6 beads are brown, representing the additional non-fertile days preceding the fertile window; the next 12 beads are white, representing days that should be considered fertile (8-19); and the remaining 13 beads are brown, again representing non-fertile days. It also has a moveable, tight-fitting rubber ring that is used to mark the current day of the cycle. Women were instructed to place the ring on the red bead on the day their menses began, and move the ring one bead per day until their menses returned. They also were told that to avoid pregnancy they should not have unprotected intercourse on the days the ring was on a white bead. If they had menstrual bleeding before day 27 of the cycle (i.e., a cycle shorter than 26 days), or if their menses had not occurred by the day after they completed all 32 beads (i.e., a cycle longer than 32 days), they were instructed to contact their provider for further assessment and advice. Women who had two cycles outside the 26 through 32 day range during the study period were advised to use another method, and were withdrawn from the study.