Hi, CIC is working on the applications received around your date at this time so you might just scale through. You are right that if the DD is expired by the time they open your application, it will be returned. We were expressly requested to provide DD that is valid for 5 months.
Even I didn't get notification (PER) on my May 12th application till September 2nd. So don't be overly worried, just keep your head up and stay hopeful. As earlier stated, it might ail through. The sky is big enough for all birds to fly