A 28-year-old woman was seen by her family practitioner for a routine pregnancy checkup at 36 weeks’ gestational age. Neither the patient nor the family physician had any concerns about the pregnancy. However, the patient did complain of unilateral swelling of her left leg, which had gradually increased over the previous 2 days. Furthermore, the evening before her visit she developed some sharp chest pain, which was exacerbated by deep breaths.