After viewing a southwest airplane flying i noticed two round-like objects in the sky moving fast. they were lower than the airplane and moving south (airplane moving west). one object was slightly ahead of the other. then i noticed another two objects behind the first two flying in same pattern. moving too quick and fluid to be a bird and not big enough to be a plane. they also appeared to reflect the sunlight. moffet air force base in close by so possibly a drone? but the shape and fluid nature of the objects made me uncertain.