Q. A 16-year-old girl comes to the emergency room for severe abdominal pain that started an hour ago at school. The pain is in the right lower quadrant and is cramping in nature. It is associated with nausea and vaginal spotting. She does not have a fever or dysuria. Her last menstrual period was 7 weeks ago and her periods are irregular. She is sexually active with her boyfriend and uses condoms irregularly. She attained menarche at 12 years of age. Her temperature is 37°C (98.6°F), pulse is 110/ min, respirations are 14/ minute, and blood pressure is 100/70 mm Hg. A pelvic examination shows right adnexal tenderness with a palpable mass and vaginal bleeding is noted. Her serum beta hCG value is 6000 mIU. A transvaginal ultrasound shows a right-sided adnexal mass. What is the most appropriate next step in her management?