Is there a chance that UFOs could be messages from other planets?
No.

The purpose of sending a message is to have someone else read it. It defies logic to send a message over light years of space and then have it do anything but broadcast its presence very clearly to anyone who might possibly want to investigate it. If the goal of these UFOs was to tell us something, they wouldn't be such elusive specimens that only appear to specific people at specific times and places, and then disappear without a trace. If UFOs are in fact meant to communicate with humanity, they are indeed rather poorly designed, because they haven't accomplished that goal very well at all!