Is a deep vein thrombosis rare after child birth or any other sort of blood clots ?

Unclear question: Pregnancy an post-partum period are risk factors for deep vein thrombosis. You may consult this site for information on this topic: http://www.mayoclinic.org/diseases-conditions/deep-vein-thrombosis/basics/definition/CON-20031922

Dvt: Not rare At the end of pregnancy as you are ready to deliver the body goes into a hypercagulsble state which is protective so that the uterus contracts after delivery and bleeding does not occur