Contraceptives, OralContraceptives, Oral, SyntheticContraceptives, Oral, CombinedEthinyl EstradiolMestranolContraceptives, Oral, HormonalDesogestrelLynestrenolNorpregnenesNorethindroneEthynodiol DiacetateNorgestrelContraceptive AgentsMenstruationMenstrual CycleContraceptive Agents, FemaleLevonorgestrelContraceptionContraceptive DevicesPregnancyContraceptive Devices, FemaleProgestinsContraception BehaviorIntrauterine DevicesContraceptive Agents, MaleNorethynodrelEstrogen Replacement TherapyFamily Planning ServicesProgesterone CongenersContraceptives, PostcoitalEstrogensEthinyl Estradiol-Norgestrel CombinationWomen's HealthAndrostenesClimactericParityRisk FactorsWomenPregnancy, UnplannedPostmenopauseMenopauseMegestrolHormone Replacement TherapyContraceptives, Oral, SequentialMedroxyprogesterone AcetateSterilization, ReproductiveSelenic AcidMenstruation DisturbancesAge FactorsAbnormalities, Drug-InducedEstradiol CongenersVaccines, ContraceptiveTime FactorsCase-Control StudiesXanthurenatesCohort StudiesAbortion, InducedReproductive HistoryPregnancy, UnwantedSterilization, TubalEstrogens, Conjugated (USP)