Interesting, I didn't know that about the blood volume increasing. Maybe that's why I've been SSSSOOOOO thirsty for a couple weeks now.
Anyway, I just wanted to say as well that these are all signs that labor is coming nearer, but it still could very well be a few weeks (which wouldn't be a bad thing, since you still have a little ways to go until your due date, although if baby was born soon I'm sure it'd be fine!!). I started experiencing that stuff with my first at about 38 weeks or so, and I ended up being induced at 41 weeks. And now I'm 38w 3d with my second, and I've been having all those symptoms for about a week, and they're just now beginning to intensify.
Hang in there! It's not much farther for you now!