Aye. It sort of dawned on me a bit when I was doing some research on the stages and effects of pregnancy because of a friend of mine.

I should note that there certainly can be exceptions to this. Had some experiences with a chick for a few years who was a bit unstable and never took any birth control.

So I guess a woman's hormones can still be an off-balance wildcard, but it's still a natural process that tends to have an established purpose that usually seems to encourage and promote some of those more positive motherly instincts and emotions.