A 29-year-old woman presents with a two-day-history of severe pain in the lower abdomen and right iliac fossa. Seven days ago, she sought medical attention after developing pelvic pain and vaginal bleeding. At that time, a urine hCG test was positive, but an ultrasound abdomen showed an empty uterus. She was diagnosed with a complete miscarriage and discharged. Her last menstrual period was six weeks ago. Her medical and surgical histories are unremarkable. There is no history of allergies. A repeat urine hCG test is performed. This is positive.