I've noticed that bubs movement changes too. He seems to be more wriggly and stretchy than 'kicky' lately, and goes through stages where he'll move lots over a few days and then is more settled, with just wiggles and shifting. Keeping a kick chart (I'd just put a tally mark when you notice a movement) sounds like a great idea, and stopping when you get to 10 so you don't worry too much!!