Quantum Menstrual Health Monitoring Study

Inclusion Criteria: * Regularly menstruating, PCOS or athlete participants aged 18-45 * Negative pregnancy test at the beginning and at the end of each cycle * Cycle lengths 24-34 days * Knowledge of previous 3 cycle lengths * Able to travel to Calgary Clinic for regular ultrasounds during the study period Exclusion Criteria: * For regular cycles * Anovulation in the last 3 cycles * Currently or in the previous 3 months, on medications that are known to impair or stimulate ovulation (e.g. oral contraceptives, ovulation stimulants, etc) * Known conditions that impair ovulation or fertility: polycystic ovarian syndrome, endometriosis, pelvic inflammatory disease in the last year, pituitary adenomas, exclusively breastfeeding * Previous surgeries impacting the menstrual cycle: hysterectomy, bilateral oophorectomy * Currently pregnant * For PCOS and athlete groups: * Currently or in the previous 3 months, on medications that are known to impair or stimulate ovulation (e.g. oral contraceptives, ovulation stimulants, etc) * Known conditions that impair ovulation or fertility: pelvic inflammatory disease in the last year, pituitary adenomas, exclusive breastfeeding * Previous surgeries impacting the menstrual cycle: hysterectomy, bilateral oophorectomy * Currently pregnant