This study takes place in Thailand, Uganda, and Zimbabwe. HIV-seronegative women continue using their current birth control method (low dose COC, DMPA injections, or non-hormonal contraceptive methods [condoms, sterilization, or no modern contraception method]) for the duration of the study. They are followed every 12 weeks for a minimum of 15 months and a maximum of 24 months, or until seroconversion. Pelvic exams, including Pap smears, are done, blood samples are drawn, and vaginal and cervical specimens are tested for any sexually transmitted diseases (STDs). Women are provided with free treatment for any STDs that are diagnosed. They complete a questionnaire on sexual behavior and contraceptive history; counseling on contraceptive use and reducing HIV risk is provided.