Let me clarify that Mom, no i didn't do that
I have moved to my new address and then had filed my application from there after i moved and subsequently updated my address in USPS website online as well, however for some reason the USPS had been still showing my new address as vacant house. Also, I had rented a USPS po box but has never used it so far just to avoid creating confusion in USCIS system. I am still not sure, why that happened bcz prior to that delivery i received 2 mails from USPS and AT and T. As you said, i wish i have used the po box instead but nothing to do at this point. Hopefully the USCIS would help me regarding to this. I am going to call them today. Thank you