My baby has been very active and he kicks every hour that makes me worry if he has enough sleep. haha. well, I think everyone will have different set of feeling and number of movements. so I think is best to see if your baby is very active and the level of movement first to find changes and patterns. so for example if you count the kicks and movements at a specific time everyday and realise there is a huge difference or sudden change on a particular day then probably you can head down to see a doctor. but I also heard that it is normal that some days baby is not as active. however I can't have much comments to that cause my baby is very very active kind where I can feel him everytime. hmmm