@troybliss.
IF you get nomination from OINP it is valid for 6 months. If in case your application is rejected by CIC, you can get another chance to get ITA using the same nomination. So its your decision entirely to continue with OINP or not. My suggestion is you should send a new DD and they will definitely return you back the old one immediately. In fact this belated nominations will prove to be blessing in disguise to you, if at all your app. is rejected.( if you get PR you can ask them to return your application )
Good luck for your PR