SPOTTING BETWEEN PERIODS

I AM 41 YEARS OLD AND HAVE HAD REGULAR PERIODS UNTIL THE MONTH OF JUNE. NOW I AM ALSO HAVING SPOTTING BETWEEN MY PERIODS. I HAVE BEEN ON A LOT OF DIFFERENT PAIN PILLS AND HAD AN INJECTION IN MY SPINE FOR SEVERE ARTHRITIS AND PROTRUDING DISC IN MY BACK. I DIDNT KNOW IF THIS WOULD MAKE A DIFFERENCE OR NOT OR IF I AM GETTING READY TO START MENOPAUSE.