Paginating a List: Controller > Adjusting Larger Page Numbers

Hey guys I am having trouble getting my header function to redirect to the last page (pg 4) of my shirts section when someone changes the url page to something too large. I have checked my products include file for any errors and it is the same as the downloaded project files. Every time I try to input a value that should redirect, it doesn't. I had a similar issue with .htaccess redirects on a couple of the shirt detail pages which after a while, and without changing any code, it worked fine. I have included the top portion of my shirts.php file which seems to be the cause of my problem. Here is the Adjusting Larger Page Numbers video. I would prefer not to do a codepen if I don't have to. If the code below is correct, could the problem be with my MAMP local server? Thanks guys!

require_once("../inc/config.php");
require_once(ROOT_PATH . "inc/products.php");

if (empty($_GET["pg"])) {
    $current_page = 1;
} else {
    $current_page = $_GET["pg"];
}   

$total_products = get_products_count();
$products_per_page = 8;
$total_pages = ceil($total_products / $products_per_page);

if ($current_page > $total_pages) {
    header("Location: ./?pg=" . $total_pages);
}

echo "<pre>";
echo "Total Products: ";
echo $total_products;
echo "\nTotal Pages:";
echo $total_pages;
echo "\nCurrent Page: "; 
echo $current_page;
exit;