c-section bleeding and pumping

I am 12 days pp. I had a c-section. I have been breastfeeding exclusively and not pumping. Yesterday my daughters pediatrician told me she wanted me to start pumping while breastfeeding because my daughter is not yet to her birth weight. I started this as soon as I got home yesterday. I have not had alot of bleeding with this c-section (this is my 2nd). Last night I started bleeding bright red and like a heavy first day of period kindof thing and cramping. I have a 3 yr old at home so it's possible I overdid it. Or could it be from all the pumping??? I'm super nervous that something is wrong. My first c-section I bled for like 4 weeks and after the first week or so it was brown and lighter. Before yesterday my blood was brown and light. I have a doc appt. in the morning thankfully but would just like some opinions.

Nurse as much as possible, don't pump, and get a new pedi who knows what the hell she is talking about with an EBF baby.

Breastfeeding causes the uterus to contract so it may have loosened something, or you could be overdoing it.

I would ask to talk to a lactation consultant at the hospital. Pumping shouldnt be the first means I would think.