Sudden drop in tire pressure

[Armand]

I checked the tires on my '10 x5 (3500 miles with Michelin RFTs) about three weeks ago and put in some air. Nothing out of the ordinary. Last night, as I started the engine, the TPM light came on and when I checked the pressure of the one tire it was pointing to, it was about five points under. There has been no sudden temperature drop and no other unusual circumstances. This has never happened to me on another car. I am suspecting a leak somewhere. Could it a "normal" thing?

I added some air and reset the TPM. This morning, there was no TPM warning. I am wondering if I should take it in to check for a valve leak or tire damage.