What Causes Prolonged Periods With Spotting At The Age Of 50?

hello, my age is 50 years, married for 22 years, i have 3 children and i always had normal periods but right now im experiencing my first monthly cycle that is not normal. the periods are very scanty and are carrying on for 7-8 days. last month a watery discharge occurred off and on, sometimes mucous like. there is no pain or fever and no pills have ever been taken by me. do you think there is an infection.