How to Grow (and Raise) an Alien...or Two

I'm trying to figure out exactly what it is within a woman that makes her obsess about her pregnancy. I was lurking around the bulletin boards on my favorite baby website and women are nuts. I can say this, because I am one of them.

Some of them have had positive pregnancy tests and yet are doubting that they are pregnant.
I have 6 positive tests at home. I keep them around so I can look at them...just to remind myself that it's true.

There are women that have miscarried before and are convinced that it's going to happen again.
Been there. I think I enjoyed my last pregnancy for a total of 15 minutes. The rest of the time was spent worrying that the baby wouldn't make it or would be born with two heads (which, by the way, would support my alien theory...). Sidenote: The baby did, in fact, make it and her one head is just beautiful. So far during this pregnancy, I have thought about miscarrying, but the slight case of ADD that I have comes in handy here.

Some women have gained weight quickly and are afraid that they're carrying twins. Please. You're pregnant. You're supposed to gain weight. What about the millions of people that are gaining weight and aren't even pregnant??? They can't even blame the weight gain on one baby.

Thing is, I haven't even hit the tip of the iceberg. There's a lot more crazy where this stuff came from.

What makes women do this? Is it a "mother bear" syndrome that makes us totally protective of our young even before they're born? Is it an overwhelming sense of responsibility and that we just don't want to fail? Do we not have enough faith that everything has a purpose and that we really aren't in control of everything/anything? Or are we all just eternal pessimists?

I'm gonna go take another pregnancy test.