Family is so important - documenting those special moments are too!  As a photographer I have been guilty of not being in the photograph, but rather, documenting my children as they were growing up.  Don't be guilty of this as you'll miss out on heirloom images of yourself as a parent with your children.  Don't worry about not looking good enough, losing weight or having your done - that moment will be gone and there's no way to recapture it!