Your baby is in the position for birth and you gotta remember that there is barely any room in there for your little one!! You will feel less movement cause its almost time! But if your worried call your doc or you can go to er and they will have to check heartbeat do ultrasound and make sure your fine ! Don't stress too much hun. I'm sure your just fine!
You shoulda got checked out a week ago,at 31w you should feel some movement everyday.i wouldnt wait till next tuesday you should go to the er or let your doc know
If you don't feel any movement with in 12 hours its always cause for concern you should feel some kind of movement. Go to the ER or call your doctor to have then check on the baby. I almost lost my son at 31 weeks because he stopped moving for 3 days.