Travelling to US with Valid petition and Visa stamped with future dates


I travelled to India with Expired Visa and with two petition.

Visa expired on Sep 27 2013

First petition is is valid between Sep 28 2013 to Sep 27 2014

Second petition is valid between Sep 28 2014 to Sep 27 2017

My passport will be stamped from Sep 28 2014 to sep 27 2017. Can I travel to US on sep 21st 2014 without valid visa for a week duration. I may have valid I797 petition and valid Visa from Sep 28th of 2014.