Completely different period now?!?!

This is my third...so I know from experience that my period always kind of changed after giving birth. But with this one, it’s really light but I have cramps and nausea, which is something I’ve never had before in my life during my period. I know a lot of people feel sick during their period, I never have. But I’m wondering if anyone else has had that change too?? I’m also wondering if it’s still just kind of weird because it’s the second once since birth?? Somethings I just can’t remember and I don’t really know if when I’m breastfeeding if it’s not really normal yet?? Anyone know anything about this topic?? TIA