That is so great that you are feeling movement!! I had an anterior placenta so I rarely felt the twins move....
I get the same thing and I am going on 14 weeks. There is only a spot that gets very hard and the rest is very soft!! My whole uterus is getting hard right now as I type!!
i used to set my warm tea cup on top of my belly and watch it rock back and forth. lol it was so funny watching them try to kick it off.
I noticed the first move when I was around 20wks. one moved more than the other throughout the pregnency. The one in my upper belly moved too much, almost all the time, but the one in the bottom moved very little, sometimes I would hve to pat on her to make her move. OHHH I really miss that now, those movements are soooo so special, and when I saw my tummy move, it was weird but very nice.
yes I could feel them moving quite early with twins
it could be one of the babies rolling over. whenever i was pregnant you could always see where they were kicking out or their little bums were poking out. my dh said it reminded him of the movie aliens (the part where the alien is about to explode out of the chest). whenever i got my bh they would radiate around the pelvic area to the back. my contractions were all in my back but my entire belly got hard and i just had this urge to push.