I'd say that the sence of inclination (being upside down) is an additional sense. but how would you discribe it to someone w/o an inner ear? While they can feel the effects of gravity change as they are inverted, the inner ear provides a huge amount of information for balance which this person would be scompletely unaware of.
Sense of hunger, sense of acceleration, sense of tempurature? There aren't the normal 5 outwardly controllable senses (touch broadly covers some of them, but they really are not a part of what constitues touch. You don't tactilly touch heat to feel it.), but they certainly provide you with information about the surrounding environment.
There are magnetic bits of metal in our brains, and it has been shown that certain individuals have a better sense of direction than others (possibly linked to the magnetic poles like many migrating animals?). If you worked hard on picking up on "feelings" that you get about things, and scientifically testing those feelings, you should be able to break them down into their constituent parts, and figure out where they come from. It appears to me that many of my gut reactions come from outside stimuli which I get from somewhere other than my common 5 senses.