Sometimes it might happen that you have an empty page in a .pdf file. The reason for this can be found in this article.
Page break not necessary
With a 'page break' mark you ensure that a new page is created. Make sure you do not insert too many page breaks or just after a page too full as this often places the page break onto a new blank page.
Do not insert a page break at the end of a quotation/document
This in fact creates an extra page.
An empty page behind a cover sheet
You do not have to create a page break after a cover sheet since the page is already fully filled in.
Note that you do not use a cover sheet as a final page. A cover sheet is always followed by an extra (empty) page.