Had a baby 9 months ago. i haven't breastfed in 6months. no period either. i had spotting for 2 days. what could it be?

Light period: Your spotting could be a lighter period. You haven't mentioned what you are using for birth control either, and one always has to consider pregnancy when there is irregular bleeding or no period. Check a home pregnancy test if that might be possible. Sometimes changes in weight can cause changes in our menstrual cycle after giving birth. Check your bmi as well.