I'm not worried yet. Though I probably should be.
Here's the deal. Every now and then I'll put a mirror up to my betta's tank. He flares up ect. Then I see what looks like a small piece of flesh hanging from behind the gills. It then proceeds to fall off my betta. This happens quite often and makes me wonder if something is wrong with him. It doesn't seem to affect any other aspect of him. It's happened as long as I've had him (almost a month). Your insight?