Background: Concerns have been raised about the consequences of enthusiastic promotion of long-acting reversible contraceptives (LARCs) for women’s reproductive autonomy, particularly among underserved or vulnerable groups including postpartum women. We developed the Birth Control After Pregnancy decision aid as a strategy for upholding patient-centered decision-making about postpartum contraception and, in particular, supporting access to postpartum LARCs while guarding against pressure and coercion. Methods: We will pilot test the Birth Control After Pregnancy decision aid in two studies. First, we will conduct an Internet-based randomized controlled trial in which pregnant women residing across the US are randomly assigned to receive the decision aid or not. Data on women’s decision self-efficacy (i.e., self-confidence or belief in one’s abilities in decision making, including shared decision making) and other outcomes will be collected via a survey administered two weeks later and compared between the intervention and control groups. Second, we will conduct a non-randomized before-and-after hospital-based study of women receiving prenatal care before and after implementation of the decision aid. Data on women’s perceived support in decision-making (i.e., feeling as though one has received adequate support and advice without pressure to make a decision) and other outcomes will be collected via a survey administered eight weeks after participants’ estimated due date and compared between the before and after groups. Implications: These studies will generate pilot data on the impacts of the Birth Control After Pregnancy decision aid and will also provide the foundation for larger-scale evaluation of the decision aid.