New posts using page.php template, instead of single.php

I've been using the "Create a WordPress Theme" course to create my own theme. It's generally worked okay, except for one huge problem: when I create a new post, it is somehow directing to the page.php template. It seems to work fine for the first 2 posts, but after I have more than 2 posts total, it starts using the Page.php template. Here's the site I'm working on:

http://www.minimalgifts.com

Notice how the first two images (Amazon Giftcard and Bamboo) are using the page.php template, while the other two images are using the single.php template. Navigating to the URL directly also doesn't work:

http://minimalgifts.com/bamboo/

http://minimalgifts.com/amazon-giftcard/

Any idea on what to fix? My code is below; I tried using Markdown but it wouldn't format correctly, sorry!

Functions.php

<?php

// Load the Theme CSS function theme_styles() {

wp_enqueue_style( 'normalize', get_template_directory_uri() . '/css/normalize.css' );

wp_enqueue_style( 'grid', get_template_directory_uri() . '/css/grid.css' ); wp_enqueue_style( 'googlefonts', 'http://fonts.googleapis.com/css?family=Indie+Flower' ); wp_enqueue_style( 'main', get_template_directory_uri() . '/style.css' ); }

add_action( 'wp_enqueue_scripts', 'theme_styles' );

add_theme_support( 'post-thumbnails' );

?>

Home.php

<?php get_header(); ?> <div class="wrapper clearfix"> <div class="grid-12 photos" id="photos"> <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?> <div class="post-square"> <a href="<?php the_permalink(); ?>"> <div class="home-thumb"> <?php if ( has_post_thumbnail() ) { the_post_thumbnail(); } ?> </div> </a> </div> <?php endwhile; else: ?> <p>There are no posts or pages here</p> <?php endif; ?> </div> <?php get_footer(); ?>

Page.php

<?php get_header() ?> <p>This is the page.php template.</p> <?php get_footer() ?>

Single.php

<?php get_header(); ?> <div class="wrapper clearfix"> <div class="grid-12 item-info"> <?php while ( have_posts() ) : the_post(); ?> <?php the_content(); ?> <?php endwhile; ?> </div </div>

<?php get_footer(); ?>

Thanks!