call hiring manager

Usually you should have a pretty good idea what happened during interview. Although everyone behaves nicely, there is subtle difference between just nice and cordial. If all you can feel is "nice", then it is finished. I would say in most cases, it is a question of "fit". and there is nothing wrong about you in those cases. You just have to mvoe on to the next opportunity, like dating. If this oen does not like you, there must be someoen out there waiting for you. Don't be disappointed. It is not you, it is them. and this is true in job hunting.