A 41-year-old female complains of left-sided chest pain. She tells you she was stabbed in her left breast with a knife. She denies difficulty breathing, and her lungs are clear to auscultation. You observe slight oozing bleeding from the wound. Her vital signs are P 98, R 16, BP 138/78, and SpO2 is 97. What is the most likely cause of her chest pain?
1) Pneumothorax
2) Pulmonary embolism
3) Myocardial infarction
4) Musculoskeletal strain