What Causes Irregular Menstrual Bleeding?

Hello. I am a 42 year old female. My last period was light with pain one day, took a pain reliever-pain subsided. I now have occassional blood when wiping after urination. One time, I felt and noticed small clots of blood. I have never been pregnant, no signs of a UTI, no STD's, no sexual activity for 2 years. What's up? Is it possible the start of menopause or something to be concerned about? Thank you.