Background: Heterotopic pregnancy is a rare complication usually seen in populations at risk for ectopic pregnancy or undergoing fertility treatment. Most commonly, heterotopic pregnancy is diagnosed at the time of rupture when surgical management is required.; Case Report: A 26-year-old gravida 2 para 1 patient had a right adnexal mass discovered in the first trimester that was conservatively managed for the remainder of her pregnancy. She underwent a cesarean delivery with right salpingectomy. Heterotopic pregnancy was diagnosed after final pathology. The patient had no risk factors for heterotopic pregnancy.; Conclusion: Heterotopic pregnancy should be suspected in patients with an adnexal mass, even in the absence of risk factors.