A 26-yeаr-оld femаle is cоmplаining оf severe abdominal pain and heavy vaginal bleeding. She has used five sanitary napkins in the past hour. Her last menstrual period was six weeks ago, and she describes a history of irregular periods but never to this extent. Evaluation of her abdomen shows rebound tenderness and rigidity in the midline of the lower abdomen. Management should include: