It sounds like baby moving as the movements get stronger it will be more obvious that those light feelings your getting are actually baby, it can feel abit weird at first and I also find certain movements feel abit odd when she does somesaults (or Im guessing thats what shes doing) it can feel really strange) but I love feeling her kick now and its so reasuring!
Leanne different people feel baby move at different times your baby could be tucked at the back where its harder to feel movements or something some people don't feel movements before 22 weeks its early yet! Try lying down quiet for 10 minutes with no tv or anything on just lie there and relax and pay attention to your body and you may feel something, this is how I felt baby for first time, when your rushing round and doing things you tend to miss the very subtle first movements taking the time to chill out and feel for them can help, I also find our little girl kicks loads more when I eat something cold, sugary or wear wear tighter trousers or lie on my front, I think in protest to being squashed bless her!