The risk of a pulmonary embolism can depend on the location of the blood clot. A pulmonary embolism is more likely if a blood clot is at or above the knee than if it is in the calf. But a blood clot in a calf also has a chance of causing a pulmonary embolism.
After the first time you have deep vein thrombosis, there is a risk of having blood clots again. Your risk can depend on what caused your blood clot and how it was treated. Your doctor will treat you to try to prevent blood clots from happening again.