1. You only have one fan, not fans.
2. The fan is supposed to operate at least at low speed when driving too slow to get enough air across the radiator.
3. It's a continuously variable speed fan. It's not like some that are only two or three speeds. It's much harder to tell when it changes speed.
4. You can't tell if it is overheating or not based on the temperature gauge on the dash. It will still be exactly in the middle when the engine is slightly overheated. If your fan is now running faster than it used to, you probably have leaking plastic parts in the cooling system.
