If I-485 denied:
If in that lower part of I-797, you see a H1 I-94 starting from 10-1-2006, then your status are good, no change of status needed.
If no H1 I-94, then you can stay till two months after OPT expiration in legal presence. You will need to change status or leave US around that time, or to see if DHS release another stop-gap rule.