 Before you get any farther after laying that tile, if it's not perfect, take care of it right then. It's one thing to maybe break one out before you've grouted it and get in there and fix it while it's still setting up. That's one thing. But once that thing is grouted in and once it's set up, you're pretty much stuck with what you got. And I don't recommend going in and trying to repair that at any point. You just really need to go in and start over, unfortunately. Sorry to be the bearer of bad news. That's just what it is with that.