First, excellent!
Mo, I asked the same thing. Yes, it's very normal and I guess it can last throughout the pregnancy. I wear a panty liner to work just so I'm not uncomfortable if it comes on. It comes and goes for day to day. I've read that your "mucus plug" regenerates itself so sometimes that is what you see coming out. As long as it isn't red or stinky I think it's fine.
Blue, my breasts were sore in the beginning and then it went away. But now the last week or so it has come back. I was rather large breasted to begin with, so sometimes I think it is just the weight and stretching that makes them ache now.
AFM, scan and appt with the periontologist next Tuesday. Also, hoping the government can resolve everything and I can go back to work soon. Lack of income when you are expecting twins in 6 months throws a monkey wrench in your plans!