Your little one is probably sleeping (babies need sleep, even when they're in the womb!) ... Hubby likes waking our bubba up when she's resting... I think I've been quite restrained in not slapping him for that one hehe.
Another thing is, as your baby grows there is less and less room in your tummy for your LO to move around, so as you approach your due date you'll probably notice a reduction in a movement - 'cause there's just not the space for it!
Try not to worry about it - if you don't feel any movements for a noticably long time, then you should phone your midwife or doctor, but I'm sure you're both fine
