TW loss of baby

I had an emergency c section on 12/14/21, due to placenta abruption. Baby passed away on 12/15/21. I am pumping every 2-4 hours during the day (not at all at night), and donating to a local family. My bleeding had stopped at around 5 weeks completely, just some clearish discharge occasionally. Today, at 6 weeks, I have bright red bleeding again. Not sure if it’s my period? Something I should be worried about? I saw the doctor at 5 weeks pp, and got the ok to start light exercise. Saturday evening I did about 20 minutes of that, could it be from that?

Thanks for reading!