I know exactly what you mean. I too am pregnant with my second child. When I first felt the movement I thought I was going crazy. I still do feel it but I'm not sure if it is the baby, my uterus or just gas. I really do believe its the baby though because I never felt any thing like this with you first. I also read online that many other moms to be experienced the same thing and confirmed it with there doctor.
OMG! im also pregnant with #2 and I swore to my partner the other day that the 8week old tiny little raspberry just kicked me haha it sure does feel like the kicking movements. Not sure whaf it is tho, maybe just our brain remembering the movement sensations :/