A 28-year-old G2P1 woman at 34 weeks gestation presents with mild vaginal bleeding and mild abdominal discomfort for 4 hours. Vital signs are stable (BP 130/85, HR 82). On examination, the uterus is mildly tender but soft. Fetal heart rate is 145 bpm with reactive NST. Ultrasound shows a small retroplacental hematoma (2 cm) without evidence of extensive separation. Hemoglobin is 10.8 g/dL. What is the most appropriate management?