How long does it take for a dvt to turn into a pulmonary embolism?

Maybe never: A DVT may never become dislodged, travel up into the right heart and out into the pulmonary vessels to cause a pe. If it does, it may only be on the order of seconds to minutes.

Embolism: Pulmonary embolism is when a clot becomes dislodged and goes to the lungs which is carried there by the normal blood flow. The answer is it can break off at anytime. Usually after a couple of weeks the clot will harden and may be less likely to break off.