Check to see if specific loop has less than certain amount of posts

I’m looking for a way to check how many posts are returned by a specific loop. So if I have a loop like this..

<?php
 $featured_post_id = get_the_ID();
 global $post;
 $args = array('cat' => '9', 'posts_per_page' => 5, 'post__not_in' => array($featured_post_id) );
 $my_query = new WP_Query($args);
 if ( $my_query->have_posts() ) : while ( $my_query->have_posts() ) :   $my_query->the_post(); ?>

And if this loop returns less than 5 posts then I want to show something. In my situation I’d be showing another loop to add more results.