How long have you been on the pill?
Or have you missed any pills?
When I first started the pill, my first month I was bleeding from the second week on (which could be mistaken for a period) but it was spotting.
If you just started the pill, then its probably your body isn't adjusted to it yet.

i have been on for a few years but I missed one of my pills for a hole 24 hrs then started that night but im a week early

You might talk to your Dr., his nurse or assistant or your pharmacist and maybe someone else might have some more info for you. You might even ask about changing your b/c pill if you have been on the same one for that long.
Good luck!