i missed them towards the end of last week
Only way to know is take a test.I agree with shveps though that if you are irregular than you prob ovulated irregularly as well. But even then it is still completely possible to get pregnant. How long ago did you miss those pills?
Have you taken a test? Any time you have intercourse protected or otherwise there is still a chance you can get pregnany. Even if you are not having periods it does not mean you can not get pregnant.
If you were having very irregular periods to begin with, that probably means you weren't ovulating regularly, so I'd say your chances of being pregnant are slim. However, if you're having unprotected sex and missed your birth control pills, there is always the possibility that you could get pregnant.