Seriously - this can be the best Christmas present you will ever get. It is all how you act as a father, and it requires dedication to be a good dad. The realization is scary, especially if this is your first, but it is also a great feeling. Congratulations.
But until the 12-13 week milestone comes around, many things can happen. Which is why a few people keep it quiet until then. Miscarriages and many other issues can come about. Still, it is definately a life game changer.