if you can feel the baby move atleast 10 times a day the baby is fine. but if your really worried call your doc
If you feel worried, eat something then lay down on your left side. If you still feel no movement within 45 mins call your doctor. I would get worried when I was pregnant about that. That is what he told me to do. I would even be doing be NST and wouldn't be able to feel the baby move sometimes even though she was.