If you find out that your girlfriend is poking holes in your condoms or intentionally skipping birth control pills in an effort to sneak around and get pregnant behind your back, you need to dump that bitch immediately.
Who knows? She could succeed in filling up her uterus with your unplanned and unwanted children and then sucking you into a lifetime of baby poop, bills, and school tuition payments before you even know whether or not you like her.
Danger, Will Robinson! Just say no.