It is a border line situation.
Technically if your score expires Sep 12 and you apply just before, it is still good. However, it is next on the deadline so I would suggest retaking.
Actually, if it expires the 12 of sep and you begin the admission process before, even if the process is prolonged for six months the score should be good.
I suggest sending an email to the UNiversity you wanna apply for and ask about your scenario. There is not a definitive answer.
regards