October is pretty late, because your scores will become official by mid-Nov, so the interviews you'd get would probably be in December & onwards. And after Dec 5th, the number of seats in classes quickly fill up, so you'd be interviewing for either very few seats or waitlist spots.
What did you score on your first attempt? If you got a 19-20 and had one low score, then maybe just see how the cycle goes. If not, then schedule the retake for October, study hard these next three months, ace it in Oct, and send your unofficial scores to all the schools you applied to. Sit tight after that point, but you may have to reapply next cycle. Silver lining is that if you score well on your retake, then you'll be all set to apply as soon as the next cycle opens up (you'll have most of your app pre-filled, you'll have your scores, and you can ask your letter writers to update your LORs). I know that may not be the best thing to fall back onto, so really try and make sure you retake the earliest you can, and that you destroy it so you can send your unofficial scores in. Good luck!
