You should feel the same NUMBER of movements (at least 10 per hour) but they may feel not as strong or different.
I just had this conversation with my doc. He said that the quantity should not change, but the feel of them might. You may not get the big kicks and jabs but will feel more rolling, pushing and stretching cuz they are running out of room.
ANyway, if your concerned call your doc. They will hook you up to a moniter till you hit 10 recorded movements within an hour. It's pretty neat, Ive done it twice. So don't worry about bugging the doc.