Acute abdominal pain in adolescents has a multitude of diagnoses to consider ranging from life-threating ones to other less obvious. In this case report, a 15-year-old girl presented with right lower quadrant abdominal pain and tenderness one month after successful surgical management of acute appendicitis. Post-appendectomy abdominal pain could easily be attributed to post-operative complications, while, in reality, a different disease state may be the cause of the pain. Physicians should have a high index of clinical suspicion, even though the temporal association of events may suggest otherwise. Hemorrhagic ovarian cyst (HOC) should be included in the differential, as it was confirmed with imaging in our case. A conservative treatment approach with progesterone was chosen, with menses resuming 2 days later, leading to regression of the cyst. The clinical significance of this case relies on the timely recognition of a disease entity, in order to distinguish it from complications arising postoperatively.