Can IB actually be mistaken for AF

Has anyone really thought AF was here but later found out it was IB? I keep reading that it’s clear to tell the difference but in the same article it will say “but many women mistake it for their period.” That just doesn’t make sense to me.

Did you bleed like your period for a few days and then later found out you were pregnant? Was it a week or a few days earlier bleeding, or was it right when af was due? Was it completely lighter then your normal af or very close to it? Did you just spot or was it a light period?

So many questions ladies 😂