Why does my MySQL RDS database deletes it's content on it's own?

My MySQL RDS database tables get deleted automatically every 7 days or so. I create tables with content for said database from an app I made, and they all get deleted after a period of days. The instance and it's database still continue to exist, just that all the tables and their contents get completely deleted. It happens everytime afer I create a table. My RDS instance is a free 12 months trial. Is it because of that that the content from the databases get deleted?