I'm 17 weeks with my twins, and what I feel in my uterus is NOT what moms of singletons have told me it would be like. I was told I would feel flutters or tickles. But I don't. What I feel is shifting. I can feel different muscles of mine pulling and contracting at the same time, and I will reach down and touch my belly and sure enough, I will discover a baseball/grapefruit sized hard lump somewhere in my uterus! Then it moves away, and the same thing will happen later, but the bump(s) always show up in different spots. This peonomenon is most often felt when I am lying down in bed at night or early morning. This happen with anybody else? Singleton mother's just look at me like I'm crazy when I try to explain it.....