Does the QR code work even though I have not published my product page yet?

The QR code is linked to the URL that you specified when you initially created the product. That way the QR code already works before you have published the product page, so that you can start printing the code onto your packaging even before you are done with adding all information about your product. However, the QR code will forward to a placeholder webpage as long as you have not published the respective product page. You can also use the URL in your own website to add a link to your seedtrace product page.