Pathfinder: "I thought current theory had it somewhere around 11?"

Yes, M-Theory requires 11 dimensions (at least it did when I last looked). As has been pointed out, '4th dimension' is simply a convention that arose following Einstein's work. Three dimensions of space had been recognised for centuries, then after Einstein time was recognised as a dimension of the space-time continuum, and thus dubbed 'the 4th dimension'. If it transpires that there are, in fact, other spatial dimensions, then perhaps that 'convention' will simply die a natural death.

"Time is what prevents everything from happening at once" - John Wheeler