I know it's common to feel a bit less as there is less room for wee baby's to move. You can try drinking some juice, laying down and counting movements. Should feel about 10 in an hour. If she seems to differ from her normal pattern or your really worried it's better to call your provider just to be safe.
I did with my second pregnancy. My doctor told me to lay down and count her kicks. As long as she kicked ten times in an hour, she was fine. She ended up kicking ten times in five minutes so I knew everything was good:) If yours doesn't, definitely tell your doctor. Mine was going to do a non-stress test if she didn't kick the ten times.