Bleeding for 2 days, 7 weeks Postpartum?

I am breastfeeding and pumping, never supplemented. Bleeding had stopped at around 5 weeks.

At exactly 7 weeks I bled for a day (bright red, filled 2 pads that day, each of them in a few minutes, similar to the first day of AF), I even had some cramping. Nothing the next day, but filled another pad the day after and nothing after that, it's been a week.

Have you experienced this, was it AF or something else? I didn't have sex, didn't exercise, I spent those days looking after my baby. I will ask my doctor next week when I see him but I was wondering what it could be, before I see him.