You can upvote (or downvote, if you want...) examples you created.
Although you won't get any reputation for doing so, upvoting your the example will influence the examples' ordering on the page.
Any previous contributors to the examples will get reputation.
On the other hand, you might consider waiting for other people to contribute so they can earn reputation from your upvote.
Note that this behavior is not a bug, as indicated in this meta post.