If you miss a couple days, then just stop taking the rest of the pack, that means you're having unprotected sex. So yes, it is extremely likely that you would get pregnant at some point. That's where babies come from after all!

So if you do not want to get pregnant, you have to actually use birth control or not have sex.
Like Cari said, if you miss two, there is no reason to stop taking the rest. Just take them when you do remember and use a backup method for a week. If you tend to forget a lot, you could try setting an alarm, using condoms, the patch, or Nuva Ring, instead.