Honey, I really don't know.
Personally, I thought I had got my period bang on time, but a few hours later there was nothing to show for it (except a very confused me)
however you will find nearly every woman has a different story to tell of her implantation bleeding, if she even had it.
Have you put yourself at risk of pregnancy?
Have you recently changed, started, stopped birth control, or other stressful events?