No. While dogs and humans mate in similar ways it's impossible for a dog's sperm to penetrate a humans egg. It might be possible to create a dog/human hybrid in a lab but I don't believe that's on anyone's to do list.
No, a dog cannot get a human pregnant. A dog cannot get a human pregnant because althout dogs and humans are mammals, they are not from the same species. Only the same species can get each other pregnant.
