well my 18 week scan went for over an over and she was really hurting me to get the baby to move out of its position because she couldnt get a clear view of pacific parts of bubs. but Eventually he/she moved and we could get them other wise she told me i would have had to have another appointment. so i beleive its just routine. Remember dont stress cause bubs will stress just be calm and have faith in ur lil one.