18wks and definitely feeling some weird things in there. i guess "fluttering" describes it.. "rolling" does, too.. as does "moving" (although i can't tell WHAT it's doing in there)!
there's definitely a lot more going on in there now than compared to, say, 10 weeks ago. so i'm pretty sure that's what y'all are feeling, too.
sometimes there's a jab here and there, but it may not be from the baby. sometimes i can SEE that it's shifted positions -- like when my belly is sticking out more on one side than the other, totally weird!