I gave birth in August, bleeding lasted a month, then after about 10 d…

I gave birth in August, bleeding lasted a month, then after about 10 days after it stopped I started spotting thought it was my period, they lasted 10 days and ended on the 10th, and here they are again today. I had an ultrasound after giving birth, they said everything is fine in normal range. Now I don't understand my period? Or what is this? Who has experienced this, please share if you have.