Nope! There's lots! Fetcon in Florida is coming up this month (okay, August) and there's all sorts of other conventions. Thing is, there's safety in numbers so the conventions you hear about are the ones that have found traction and proven themselves to be safe/non-scammy. The big names are definitely Exxxotica and AVN but it's the same as how there are other comic/anime/gamer conventions besides SDCC and Blizzcon. The bigger names get more money and therefore more attention.