Ah yep......doing the same here too ...very tired, anti social, waddling like a penguin and completly over it....
I tend to think that towards the end, you withdraw into yourself a little bit as your body will be drawing on every little bit of strength and energy to be able to give birth, so its probably just your bodies way of saving all its resources for the big day...

And of course it could be just your body saying also...Ive been doing this for 9 months now, enoughs enough!!!! lol!!!