I didn't know I was pregnant....

I'm watching this show on TLC and I can't believe these women didn't know they were pregnant until their baby was on it's way out of the birth canal. Seriously. How is this possible?? Okay, irregular periods, minimal weight gain, no morning sickness, I can see that. But HELLOOOOOO you can totally feel and see your baby trying to punch it's way out of your belly. There's no way in hell you can write off the feeling of someone playing kickball with your cervix as gas or food poisoning. There's gotta be major denial, lack of knowledge about the human body, and a whole lotta mental illness for someone to not know she is pregnant.