Your baby should be active right till the time of delivery. If you feel a change in his/her movements, then this could signal that your baby is not completely comfortable and you must report it to the doctor.
Another thing to watch out for is an amniotic fluid leak and whether the fluid is stained with a brownish greenish discharge. If you notice a stain, it means your baby has passed meconium (the first stools). You must immediately report this to your doctor and head to the hospital as your doctor would want to monitor the baby.