I believe the "Change Oil Soon" light always lights up when you start your car (to verify it's still functioning), but will go out after a couple seconds. When it determines you're ready for an oil change, it will remain lit for about 10 seconds. It has happened to me only once that way, the rest of the time, I've changed my oil before the counter determined that I needed to. I put on about 12K miles a year, and change the oil every 4 months - 10W-30 Nov-Feb, 30wt Mar-Jun & 30wt Jul-Oct. In the dead of winter my car's starting temperature is never below 50 degrees F. Spring, Summer and Fall it's usually around 70 degrees F.
Regards, Gary in Sandy Eggo