Insights in Endocervical Mucus Secretion

Inclusion Criteria: * Normal menstrual cycles of 25-35 days in length for at least the previous 3 cycles * BMI \>18 and \<35 * Serum p4 \>= 3 ng/ml on single sample collected between days 18-25 of self-reported menstrual cycle * Flexible schedule allowing blood draws on less than 48 hour notice * In good general health * Commit to using non-hormonal contraceptive methods without spermicide during study period except those prescribed in the experimental protocol * No objections to taking study drugs * No objections to refraining from intercourse the night before any sampling and willing to use condoms during vaginal intercourse Exclusion Criteria: * Oral contraceptive use or other hormone supplement within the preceding 2 months * Current cervical infection * Evidence of abnormal cervical cytology * Use of any IUD for contraception * Long-acting hormonal contraceptive use in the past 12 months (e.g., Depo-Provera) * Contraindications to study drugs * Current or past pregnancy within the previous 6 months or currently trying to conceive * Desiring to conceive in the next 8 months * Breastfeeding in the past 2 months * Diagnosed diabetes or metabolic syndrome * Diagnosed Polycystic Ovary Syndrome * History of, or self-reported, substance abuse * Smoker * Previous infertility treatment excluding male factor issues * Use of an investigational drug within the past 2 months * History of excisional or ablative treatment procedure on cervix (i.e., LEEP, Cryotherapy, Cold Knife Cone) * Current treatment for a vaginal infection such as bacterial vaginosis * History of venous thromboembolism (VTE) or inherited thrombophilias