Hypothetically if god created the earth in 7 days and he made the entire universe at that rate the Milky Way galaxy would not even be finished yet. Astronomers have estimated there may be as many as 1 trillion planets or stars in the Milky Way. Assuming the earth is an average size planet that would mean it would take 7 trillion days just to make all planets and stars in the Milky Way which is equal to 19.1 billion years which is several billion years longer than the calculated age of the universe. So there would still be billions of other galaxies waiting to be created.