This is essentially a personal decision. If it will upset you to read, view, or watch fanworks based on your works, then don't.
Authors are sometimes advised to avoid reading or acknowledging fanfiction transforming their own work, as it is in theory possible that an author could read a story, go on to write something similar, and face a claim by the fan that they copied the fan's work. There are many reasons to discount this risk, the least of which is that U.S. case law is all in the first author's favor: no court is going to be receptive to a claim that a later work by the first author in the same universe infringes the fanwork. Among other things, when people begin with similar premises, it isn't at all surprising that they will end up with similar ideas — but U.S. copyright law protects the specific expression of an idea, not ideas. Even if a fan work is similar to a later work in the same universe, similarity of ideas (say, how wand magic works in Harry Potter) isn't sufficient for a copyright claim.
However, not being able to win doesn't erase the possibility that someone could threaten to sue. The real issue is that it doesn't take a fanwork to generate a threat! If an author reads fan mail or online reviews, they might encounter a fan's ideas about what should happen with the characters; if they read other books, they might encounter a storyline or character similar to a storyline or character they might later use. In fact, the typical author-versus-author infringement case involves claims that one work copied another, apparently unrelated work.
The OTW's mission includes explaining the difference between ideas and expression. A lot of people may have the same idea about what should happen on the next season of House; but if they each write different stories expressing the idea differently, then those stories don't infringe each other.
