You can create a conditional text field that displays the word "pages" instead of "page" in conjunction with a page count field if your document contains more than one page.
Place the cursor in your document where you want to insert the page count.
Choose Insert - Field - Page Count, and then enter a space.
Choose Insert - Field - More Fields, and then click the Functions tab.
Click "Conditional text" in the Type list.
Type Page > 1 in the Condition box.
Type Pages in the Then box.
Type Page in the Else box.
Click Insert, and then click Close.