PHP, Fire cookies on condition of pages

I'm having some trouble firing cookies on the condition of what page the user visits first.

Code below fires a cookie if on pages 2641, 2998, 2949 and no cookie exists. However, how do I do it to fire a different cookie if user is on any other page on the website if no cokkies exist?

Rule: Two cookies cannot exist. Just one or the other.

Any help much appreciated :)

if (is_page([2641,2998,2949]) && !isset($_COOKIE['ppc_campaign']) && !isset($_COOKIE['organic'])) {

    $ppc_cookie = "ppc_campaign";

    $ppc_value = (!empty($_SERVER['HTTPS']))
    ? "https://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'] 
    : "http://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];

    $path = "/";

    setcookie($ppc_cookie, strstr($ppc_value, '?'), time() + (86400 * 28), $path);

    $acf_applicationLink = $ppc_value;
    }   

else {

}