7 weeks post partum on the mini pill question

Ar

Ok so seven weeks post partum and on the mini pill, which I started a week ago but just woke up with bleeding and mild cramping. Obviously I know it’s my period at this point but is it common to bleed randomly on the mini pill, I assumed if I was on it if I was going to get a period while EBF it would at least wait until the end of the pill packet???