Hello PH12,
Thank you for posting here in the Community. I'm here to assist you with your concern about the 941 form in QuickBooks Desktop.
If you're referring to line 1 of the form for Q1, please know that it'll only count and show those employees paid with a pay period that included the date of March 12, 2019. For more insight into 941, such as line 1, I'm adding an article that I recommend:
How QuickBooks Populates The 941.
The basis on the amounts from the form should be a pay date from the last quarter since the data doesn't depend on the week ending for reporting taxes. To learn more about Constructive Receipt work, you can visit the link from the IRS publication (scroll down to page 13):
https://www.irs.gov/pub/irs-pdf/p334.pdf.
That said, you can review the dates entered on your paycheck to ensure it'll show the right information.
Please be sure to let me know if there's anything else I can do to help you regarding the federal forms. The Community is always available to help.