update_post_meta is Updating with two page id

I am writing a code to count the number of views of post. For that I am using update_post_meta and passing appropriate parameter.

I am calling a function on add_action('wp', 'function_name'); in functions.php.

My problem is, whenever I am loading the page in Chrome, it works fine. But when I am loading the page in Mozilla Firefox, it is updating the page view counts for two/three page's id in wp_postmeta table.

Should I use some other action hook?? If yes, which one? Can anyone tell me, what the issue is??

Thanks