I felt the "flutters" at around 18-20 weeks, and then at my u/s she was jumping, and waving, but I couln't really feel it, a lot of times it would happen, but I didn't have time to concentrate on it because it would be gone too fast!!
Now a couple of weeks after that around 22-now I am 29 weeks this week, she is really kickin, sometimes so hard I almost pee!! They are REALLY low, like right above my bikini line also, Sometimes at work I can see the bump jump, but before I have time to show anyone, she stops!!