If you are already in H1 status and you have filed for extension you are fine.
(since you already have the receipt)
If your current status is other than an H1 and you have applied for change
of status, and you may have to go back on/before expiry date on your current I-94, then wait for your H1 application to get approved, apply for visa
and enter the US on your new H1 status(and a new I-94) All new H1's would
have a start date from Oct 1 so all this will have to be done after that date.
inqsit