Can't remember if you had already cooked the egg in your hands or accidentally mixed it with uncooked eggs ? Don't panic, there is a very simple technique to determine the condition of your egg.
Place it on a flat surface and rotate it on itself, if it turns smoothly, it is cooked . If your egg has trouble turning or stops quickly , it is because a liquid mass is still present in it and therefore you have not cooked it .
Indeed, a liquid mass and in particular the yellow which has a different mass from the white, will slow down the effect of rotation. It is the same principle of action as a Powerball.