Breastfeeding Etonogestrel Implant Study

Inclusion Criteria: * Pregnant women or women who have delivered vaginally and by cesarean section within 22 hours (2-hour window will allow for implant insertion by 24 hours postpartum) * Aged 13 and older * English or Spanish speakers * Deliver an infant at UNM Hospital at \> 37 weeks gestational age * Intend to breastfeed * Desire the implant as a method for contraception * Agree to randomization * Must have a working phone (study questions to be answered through phone calls or accessed electronically by a link sent through email or text message) Exclusion Criteria: * Under age 13 * History of breast cancer (screen by past medical history) * History of undiagnosed vaginal bleeding (screen by past medical history) * Head trauma that affected pituitary function (screen by past medical history) * Prolactin insufficiency (screen by past medical history) * Previous lactation failure (defined as no lactation within 5 days postpartum) * Any contraindication to lactation/implant use including diseases transmittable by breast milk (screen by past medical history) * Liver dysfunction (screen by past medical history) * Use of drugs that inhibit lactation (screen by medical history) * Sensitivity to the components of the ENG implant (screen by past medical history) * Contraindications to use the implant by the (US MEC) (screen by past medical history) * Active labor * Delivery at \< 37 weeks gestational age