Late af was it chemical pregnancy?

[scrunchy]

My period started 10 days late .
Yet 10 days ago I had cramping as if it was coming for 5 days.negative pregnancy tests
Only second period since givubg birth last year ,am still Breastfeeding.
Was it just late ? It's extremely heavy now ,or a chemical pregnancy ,as I'm mystified why the cramping 10days ago.its never in my life been this late before

[ColdTeaAgain]

My periods were all over the place when they started again after breastfeeding.

[scrunchy]

I've always had them like clockwork once they return ,it's my 4th baby ,they return usually 9months and then every 30days .