NorgestrelLevonorgestrelContraceptives, OralContraceptives, Oral, CombinedContraceptives, Oral, HormonalContraceptive Agents, FemaleEthinyl EstradiolContraceptives, Oral, SyntheticDesogestrelContraceptives, PostcoitalEthinyl Estradiol-Norgestrel CombinationContraceptive Devices, FemaleContraceptive AgentsNorethindroneContraceptionContraception BehaviorMenstruationContraception, PostcoitalIntrauterine Devices, MedicatedContraceptive DevicesNorpregnenesProgestinsCervix MucusContraceptives, Postcoital, SyntheticPregnanediolMedroxyprogesterone AcetateMenstruation DisturbancesMestranolIntrauterine DevicesAndrostenesMenstrual CycleCyproterone AcetateProgesterone CongenersUterine HemorrhagePregnancyFamily Planning ServicesOvulation InhibitionContraceptive Agents, MaleLynestrenolNorpregnadienesContraceptives, Postcoital, HormonalPregnancy, UnplannedMenorrhagiaEthynodiol DiacetateMegestrolMifepristoneNorethynodrelHealth Knowledge, Attitudes, PracticeCase-Control StudiesPregnancy, UnwantedMetrorrhagiaPolycystic Ovary SyndromePharmacists' AidesRisk FactorsParityEstradiol CongenersEstrogensGonadotropin-Releasing HormoneTransdermal PatchDysmenorrheaDrug ImplantsOvulation InductionGreat BritainQuestionnairesChlormadinone AcetateEndometriumThyroxine-Binding GlobulinIntrauterine Devices, CopperAbortifacient AgentsFertilization in VitroHirsutismContraceptives, Oral, SequentialNatural Family Planning MethodsTime FactorsSterilization, ReproductiveNandroloneEndometrial Ablation TechniquesNonprescription DrugsOvulationVaccines, ContraceptiveIntrauterine Device ExpulsionNicaraguaXanthurenatesAge FactorsSex Hormone-Binding Globulin