Weird tingling between shoulder blades towards right side 4 mos since giving birth. woke up with tingling replaced by bad pain. what could it be?

Entrapment of nerve : I don't know what giving birth might have to do with this unless you have gained excessive amounts of weight in which case there's a possibility you are experiencing an entrapment of a small nerve twig that runs down the center of your back between shoulder blades. That being said, there are other possible explanations so a neurological examination is in order.