SERVICE ENGINE SOON LIGHT

THIS LIGHT COMES ON EACH TIME I START MY CAR AND GOES OUT RIGHT AFTER STARTED. JIFFY LUBE USED TO CHANGE MY OIL AND CHECK UNDER THE HOOD EVERY 3 MONTH--I STOPPED DO IT---RETIRED AND DON'T USE CAR MUCH.
I CHANGE MY OIL ONCE A YEAR NOW---IT LOOKS THE SAME COMING OUT AS IT DID GOING IN. I ONLY DRIVE IT ABOUT 25 MILES A MONTH AND 2 TIMES A MONTH TO THE KROGER STORE & WALMART---THAT'S IT! DO I NEED TO WORRY ABOUT THIS LIGHT THAT COMES ON AND GOES OFF ON START? THANKS. OLD LADY IN TEXAS.