With my son 4 years ago I felt the first movement (that I could recognize for sure, anyway) at work, when I was sitting in my desk chair. It was a hard little THUMP- startled me so much that I yelped really loudly and jumped out of my seat! Not cool when you work in a high school!
With this one I thought I felt the "swimming fish" thing a couple of mornings ago for a few minutes when I was sitting real still, but I haven't felt anything since so now I'm thinking it was just gas. I'm only 15 weeks, so it's early.