It depends on the state. What state are you in?
In my state, edged weapons can generally be carried openly but they do not have the same protections as firearms and localities can make their own regulations. As a result there is a patchwork of local laws that prohibit the carry of blades. I only carry my blade when I am in an area where I have researched the local laws due to the lack of state preemption in this field. In my state it is safer from a legal standpoint to open carry a firearm.
I sometimes carry a knife in addition to a firearm, but I believe a firearm is a superior armament when it has ammunition.