Combined Oral Contraceptive (COC) Antiretroviral (ARV) Pharmacokinetics (PK) and Pharmacodynamics (PD) in Malawi

Inclusion Criteria: * Can provide informed consent * Women ages 21-35 with known HIV status * If HIV negative must have had an HIV test within the last 3 months * Intend to stay in Lilongwe region for the duration of the study * Desire to prevent pregnancy for at least the next six months * Desires to use LoFemenal for contraception * Has no known history of infertility * Has intact uterus and at least one ovary * Has regular monthly menses defined by menses occurring every 21-35 days * Has not used another form of systemic hormonal contraception within the last six months. * Has no contraindications to the combined oral contraceptive LoFemenal which include; any thrombophlebitis or thromboembolic disorders; cerebral-vascular or coronary-artery disease (current or history); thrombogenic valvulopathies; thrombogenic rhythm disorders; major surgery with prolonged immobilization; diabetes with vascular involvement; headaches with focal neurological symptoms; uncontrolled hypertension; known or suspected carcinoma of the breast or personal history of breast cancer; carcinoma of the endometrium or other known or suspected estrogen dependent neoplasia; undiagnosed abnormal genital bleeding; cholestatic jaundice of pregnancy or jaundice with prior pill use; hepatic adenomas or carcinomas or active lever disease, as long as liver function has not returned to normal; known or suspected pregnancy. Exclusion Criteria: * Hemoglobin \< 10 mg/dL. * Body mass index \< 18.6 kg/m\^2. * Using any drugs known to interfere with cytochrome P450 system (such as rifampicin, phenytoin, carbamezapine, among others) * In the opinion of the PI or study staff the individual cannot complete the study * Cannot be adherent to other medications. Additional inclusion criteria for the 3 HIV+ women on antiretroviral therapy: * Must be on antiretroviral therapy which includes nevirapine for at least three consecutive months immediately prior to enrollment into the study * Must report adherence to medication and medical visits * Must be willing to use a barrier or backup method of contraception.