I think it is just like Pericat said. Pregnancy is a life-changing event, a preclude, even, to a bigger life-changing event to occur in roughly nine months.
As a male, it may help you to understand, say if I use the example of the lottery. Imagine on a Saturday or Wednesday watching the lottery numbers being drawn on the tele and you have an inkling that those numbers you have. But you don't have the ticket infront of you, it's in the car!
Now would you manage to get your ass of the sofa/chair, there and then and retrieve the ticket and check it as soon as possible or would you wait all night, until the morning before it is confirmed to you whether you are a millionaire or not?