Check your contract for an "expected occupancy date" for the unit you own. You definitely cannot stay before that date using your own points. But, after that date you may be able to use your points even if it isn't September yet.
Remember reservations are only subject to the 11 / 7 month booking windows. As spiceycat said, even if your points are not available right now, there is nothing that would keep you from BOOKING a room now.