RSS Feed only Showing most recent 13 posts

For some reason my wordpress feed is only showing the last 13 posts (strangervilleblog.wordpress.com/feed). I currently have 14 posts on the wordpress site, so the oldest post is not showing on the feed. In Settings–Reading I have “Syndication feeds show the most recent” set to 50. I can’t figure out anything else to try. Can anyone help me figure out why the oldest post has fallen off the feed? THANK YOU!