Camembert can age properly within 21 days and be "à point" by day 28. To age it longer you will need a far lower temperature than classic Camember and good pre-draining or smaller cutting of curd (Camembert AOC curd it ladled). Watch out for runny texture because it is a sign of ammoniation. An undesired smelly spicy quality for this cheese - a sign that ammonia is taking over. Properly ripe Camembert should be supple and soft, elastic and even gooey -but never runny.
Yes, judge it by the smell and by the feeling of your skin below the thumb when your hand is close-fisted. Some people compare it to the feeling of pressing your eye when your eyelid is close. Smell should be mushroomy, not pungent. If you are not sure whether or not your cheese has ammoniated, try drinking orange juice right after you eat the cheese. If it passes, the cheese is fine. If it's utterly bizarre in your mouth - the cheese is over the hill. (by the way, this is a bad pairing even with perfect Camembert...)
Best suggestion; head on over to a good cheese shop and buy a Camembert de Normandie AOC (any brand). This is the most proper example of a perfect Camembert consistency. Enjoy it and memorize the texture, aroma, flavor profile and rind appearance. Take photos to later compare with yours. Most other Camemberts are not as good and heavily stabilized so they lack the flavor and proper texture. A good Coulommiers or Brie such as Fromage de Meaux will also work