No...Earth pules inward because it is so big, creating its spherical (oblate spheroid to be exact) shape. Law of Conservation of Mass, the Earth has always weighed the same exact amount since the day it was created. (except for collecting dust particles from space, comets and asteroids, the subtraction of mass when we send stuff into space, etc.) Even when another person is born, it is balanced by all the food the mother had to eat while carrying it. 7 billion cannot affect the Earth's global movements, vibrations, or whatever else you said, enough for anything to be measured. If you throw a bouncy ball into the air, the Earth moves, because the distance between the Earth and the ball increased, changing gravitational pull. It would be such a small number, you would need more space to write it than that which is needed for pi or something... So the forces of gravity, vibrations from plate tectonics, the action of Earth spinning and spinning...they're just so great us people don't make a difference in this respect.
Lol, just saw the answer before mine...now them's some numbers...