Hmmm, if there's no mould yet, and the cheese is getting liquidy around the edges, it could be that the surface is too wet and you've got a wild geo party going on. Geo will liquify the cheese, and it will keep the surface too wet for PCad to show up. So, it could be that you've just got geo gone wild. That's what happened to my first brie make at least. I think the curds were too soft and wet, and never drained properly.