You could actually be feeling it when you're asleep. Baby tends to wake more at night when you're relaxed.
It's better than the dreams I've been having !!
I had one the other night that I went to the docs, and he said that he needed to look at my bellybutton. He dug around in it, and pulled out 3 loops of yellow string, like plastic, and said 'Yup, just as I thought, gonna have to cut these off' I was horrified !!
Then he discovered he didn't have any scissors, so he made me hold the instrument that was keeping them pulled tight out of my belly button, and left the room.
Then another doctor came in looking for him, and when he saw me sat holding this thing, he said 'let me guess, he's gone to find scissors'. I just nodded dumbly. Then he gave me a pair of scissors and expected me to cut them off myself !!! I woke up then, thank god. Sorry... just thought I'd share
Pregnancy does make you have really vivid dreams !!!