As long as the high-speed fan kicks in before the temp. gauge needle passes, say, the L, and then the temp. reading comes back down, sounds fine to me. Temperature should go up while idling after being driven because the water pump is turning slower and airflow over the radiator is reduced. Once you get going again, the temp. should come back down to its regular value. As long as the needle sits in the NORMAL range whilst driving, you ought to be fine. The gauge is not a precision instrument, and there's a separate sensor for telling the engine management computer when the higher fan speed is needed.
It's also conceivable you're still purging the air from your coolant system (it needs to "burp"). In such a case, you'd see periodic upward "spikes" in the gauge reading.
Anyway, you're keeping an eye on your temperature, which is certainly a good thing.
I presume you're watching your coolant level, checking for puddles beneath the car, etc. If something does indeed go wrong, you'll catch it quickly.
