Excluding Pages from Recent Posts in Sidebar

Okay, I have read the other posts. I am not using a widget, just the plain install of version 2.2 My code doesnt have the post_type=’post’ or any if statement. I am at a lost how to exclude PAGES from my recent posts listing.

Here is my code:

<h2><?php _e('Recent Posts'); ?> </h2>
<ul>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<li><a href="<?php the_permalink() ?>"><?php the_title() ?></a> <span class="date">posted on <?php the_time('M.d') ?></span></li>
<?php endwhile; endif; ?>
</ul>

What do I need to add to tell it if it is a page not to include it? Thanks for any assistance.