First period after baby?

I had my son in July and I got my period 2 days ago. It's definitely different than before I was pregnant. I'm having constant cramps that hurt very badly. I'm also very constipated. Sometimes I can't tell if it's just tummy cramps or if I have to poop. And I'll literally sit in the bathroom for like 15 mins and nothing happens. I've also been having my stomach make really weird noises. Like liquid inside is moving? Any tips on how to help me in this situation? It would be very helpful 🙌🏻