Engine Tapping

Hey guys,
I have an 03 Ford Mustang GT that has 30,000 miles and have noticed lately when starting it up cold in the morning for the first time that the engine makes a tapping noice starting around 2K rpm..it goes away as the engine warms up and i'm careful not to ever get on the gas and rpms while the engine is cold..but what could this noise be? Is there anything I should be worried about? Car performs fine..just makes a tapping noise like the oil isnt completely circulated around the engine yet?