If I feel anything, it sort of feels like a slight tightening and ripples. But then if I sit there and concentrate, I can almost always feel that, so I also think I might be sort of willing myself to feel it. I have "twinges" from time to time, but who knows if they are baby movement or gas pains or a slight muscle cramp.
Descriptions others have given (flutters, bubbles, my MIL said it was like a fish swimming through your tummy) don't really connect with me yet--I just don't understand how I could feel something that subtle. I feel like I have gas bubbles and whatnot going through there all the time (or, more annoyingly, I think "Is that the baby?" and my stomach sort of jumps like a nervous response)--how could I possibly distinguish a "flutter"? I think I just have an overactive tummy (and imagination), LOL.