There is some debate regarding what classes as a "sense" but in actual fact we have nearly/over 10.Radiolab did a small bit on this. Namely, they said that birds use the earth's magnetic field to guide them on their migrations. But, I think this would be like a seventh sense if it existed in humans our sixth sense is equilibrioception. Radiolab also did a cool show called "Where am I?" where they talked to some guy who lost his sense of equilibrioception.