Gill - nope, mine looked like a gloopy clearish yellowish oyster. It was gross If only there were a sure fire way to get labour started naturally, I reckon you would be onto something there!!
Do as much as you feel comfortable doing. Obviuosly dont overdo it, but if you are still able to walk without discomfort, its super good for you.
I hear you on the birthing centre. I am hoping I dont go over so I can still be in our FBU cause I bloody hate the hospital too!! Who wants to share a room with someone