Validation of Effectiveness on NaturalCycles Users

Inclusion Criteria: * Wants to avoid pregnancy for 13 cycles. * Is willing to rely solely on Natural Cycles as their sole contraception method for 13 cycles. * Is not currently using permanent contraceptive methods, such as sterilization (of either the user or their partner), or hormonal methods, such as the hormonal contraceptive implant or IUD. * Has an intact uterus, both ovaries and both fallopian tubes to the best of their knowledge. * Has an average cycle length between 21 and 35 days. The user anticipates heterosexual intercourse at least once a month in the next year. * Is willing to enter data on a daily basis and perform pregnancy tests as requested by protocol. * Is willing to complete a satisfaction survey at the end of her study participation. Exclusion Criteria: * Has EU-citizenship * Has had a Depo-Provera injection in the last 10 months or has had less than three consecutive, spontaneous menstrual cycles since their last injection. * Has had less than three consecutive, spontaneous menstrual cycles after removing a hormonal implant. * Has had less than three consecutive, spontaneous menstrual cycles after the end of a pregnancy. * Has had less than three consecutive, spontaneous menstrual cycles since she last breastfed. * Has (or partner has) known fertility issues, such as infertility and sterilization, or have been advised by a healthcare professional that they may have difficulty conceiving for any reason. * Has a medical condition possibly impacting fe…