Rather test your clean function. When considering what to test, think of the functional (rather than structural) units, and write a test for each of those if possible.
So for example, when you create an Announcement, you validate the fields. When a user goes to the home page, you'd display all announcements, using pagination. And when an announcement is selected, you'd display it. So from that, for example, you could test your pagination and validation, etc.