Cramping

My LO is 13 months old and last month I had one day where I thought I had started my period. I bled for a few hours and by the time I got home from work it was done with. It’s been like 31 days since then but I’ve been randomly getting cramps. They just come up out of nowhere and I never bleed at all so I’m not sure what they are all about. Has anyone experienced this?

Side note: That one day of bleeding was the first “period” I’ve had the entire time I’ve been nursing.