2003 Ford Focus Check Engine

Hi, I just got in my 2003 Focus SE and when I pulled away I noticed the Check Engine Light was blinking.

It went away about a mile later and never experianced any issues while driving.

I drive a lot and have 78,000 miles on it.

The manual says if it's blinking it is mis-firing, but I have not noticed anything out of the ordinary.

Any ideas?