Doctor, I gave birth by cesarean section for about 14-15 days and I didn't see any more discharge, but after a few days and until now I sometimes have blood or dark brown discharge, what is it?

I had a caesarean section two and a half months ago and still bleeding. On ultrasound, the uterus was clear, no fluid was seen. I don't have any pain or fever. Only across the incision line it is numb. The doctor asked me, did I have a maternity leave? If so, how should I treat it?