well i usually use pills too but my insurance ran out recently so i had to go to the clinic to get them and had to wait for my period to start to start them so know im offically on the pill as well.
As you probably already know, those pills are not meant for a regular form of birth control. They can really mess with your body and your cycles. I would doubt that you are pregnant, it's probably just your body dealing with the pills. You might want to think about doubling up on your birth control method, such as using the regular pill AND a condom so you won't have to worry next time a condom breaks. :)