Most women experience some form of postpartum bleeding to various extents. In most cases, it usually starts off heavy for the first few days after delivery. Afterwards, the volume of vaginal bleeding tapers off over the next few weeks to be more like spotting or brownish staining. This occurs as the womb shrinks back down to its normal size and whatever blood is still left within the uterine cavity will gradually be expelled.
This can go on for up to 6 weeks postpartum and is no cause for alarm. To still have bleeding 11 weeks postpartum is unusual and you should see a gynaecologist to exclude retained products of conception (mainly placenta/membranes) which is the most likely cause in this case. This can be diagnosed with a pelvic ultrasound scan.
Other causes of postpartum bleeding include uterine rupture, vaginal or cervical tears, failure of the uterus to contract (uterine atony). However, these present with more acute bleeding earlier and you would be in a lot of pain or have experienced a drop in blood pressure already.