Hello and welcome to the QuickBooks Community, info-blackfoxroo
We'll be happy to support you in correcting your weekly payroll.
To do this, you will need to rollback (delete) the incorrect pay period and then amend the payroll schedule so that it begins on the correct week.
If you have submitted the period to HMRC, you will need to select the late reason for the next FPS submission as option H - correction to earlier submission.
So that we can provide the steps to rollback, please confirm the version of payroll that you're using - QuickBooks Online Standard Payroll or Advanced. Thank you.