Can starting back on birth control 7 days before my period is due make it 8 days late?

I just took a pregnancy test and it was negative, but my period is never late. My last two periods were July 31st and August 30th. I should have started September 30th. I had some real bad cramps at the beginning of the week, and I thought it was because my period should be coming, but it's still not here.Can starting back on birth control 7 days before my period is due make it 8 days late?
If you were off BC, then started taking it a week before your period is due, it would *definitely* screw with your cycle. You're supposed to start a new pack on the first Sunday of your period, to keep you on schedule.