In the code below, I am querying for 15 posts, I am only getting 10 posts (there are 12 posts in all in the category). Shouldn't I get all 12?
<?php $args = array(
'numberposts' => 15,
'cat' => 13,
'orderby' => 'post_date',
'order' => 'DESC',
'post_type' => 'post',
'post_status' => 'publish' );
?>
<?php $the_query = new WP_Query( $args ); ?> <!--gets all posts from category 12 -->
<div class="roll">
<?php while ( $the_query->have_posts() ) : $the_query->the_post();
echo '<span class="thumb"><a href="';
the_permalink();
echo '">';
the_post_thumbnail('small');
echo '
</span>';
endwhile; ?>
</div>