Before I can accurately answer.. Did you miss your 'period pills", or did you miss the ''active pills"??
Many women will have breakthrough bleeding during pill use, where they may bleed the week before their actual "period". This is considered normal, and a woman should keep taking her pack of pills as usual. You should not stop taking the pill in the middle of the pack due to breakthorugh bleeding.
If you missed your "period pills", then it doesn't matter. They are inactive pills and you do not have to take them, they are more for reminder purposes.