Hichamitooo

I found this function but this add the featured image after a paragraph.
how to make it add it in top left corner?

add_filter('the_content', function($content)
{
   $url = wp_get_attachment_url( get_post_thumbnail_id($post->ID) );
   $img = '<img src="'.$url.'" alt="" title=""/>';
   $content = preg_replace('#(<p>.*?</p>)#','$1'.$img, $content, 1);
   return $content;
});

help please