Even if you are vigilant mold can go undetected for quite some time, it can grow unseen behind surfaces such as walls, floorboards and carpet making it difficult to detect.
If you are already seeing or smelling mold, chances are high that the problem has been developing for a while.
Delaying mold remediation can cause the problem to propagate and become more extensive posing a serious health concern, especially if there is black toxic mold present.