Introduction: Cesarean rate increased in recent decades worldwide. One of the consequences of the increased cesarean rate and repeat cesarean is the significant increase in cesarean scar pregnancies (CSPs). Diagnosis of a CSP is more difficult when there is a heterotopic pregnancy in a non-assisted pregnancy. Case Presentation: The patient was a 34-year-old G5P2L2Ab2 referred for spotting in Shahidan Mobini hospital, Sabzevar, Iran in 2016. She had a history of 2 cesareans and 2 abortions. Three ultrasounds were performed showing a gestational sac in the lower segment of the uterus with different diagnoses: 1) with hemorrhage over it, 2) with the 2nd gestational sac over it, which was diagnosed as missed abortion, and 3) with an echo-free and irregularly region supporting the 2nd sac or a clot in the lower part of the uterus. The increased local vascularity suggested a level of placenta accreta, partial mole, or trophoblastic reaction. Since the first diagnosis was missed abortion, curettage was performed. Due to the continuation of severe bleeding, abdominal hysterectomy was performed. The patient was discharged in good condition after 3 days. Conclusions: Heterotopic CSP does not have any specific symptoms, which caused it to be easily misdiagnosed. Physicians should use precise diagnostic tests in case of controversial test results.