Fibrinogen is usually ordered with other blood clotting tests. It helps your doctor to evaluate your body’s ability to form a blood clot. Fibrinogen may be ordered as a follow-up to an abnormal Prothrombin Time (PT) or Partial Thromboplastin Time (PTT) and/or an episode of prolonged or unexplained bleeding. This is a non-fasting test. Expect results in 1-2 business days.