What Causes Delayed Periods While On Contraceptive Pills?

I am taking the birth control loseasonique. However, it has been a week and a half since the non-hormonal pills have been taken and i have yet to get my period. I started the new pack in hopes it was just a miss hap but i have realized that i have had cramps for just about 4 weeks. I am not pregnant. I took numerous tests to confirm that. Any suggestions as to what is wrong?