What Is The Irregular Spotting After I Got My Tubes Tied?

Hi doctor im 30 years old i had my tubes tied 7 months ago after having my third child i started my period two months after delivery and proximately 2 months ago my period started at the beggining of the month amd lasted for 3 days and then two weeks later i started just spotting there was no need to use tampoon or pad and same happened this month please help