No one really knows how many changelings were present during the invasion of Canterlot. Unfortunately for the rest of the world, it also means that the love explosion scattered them all over the surface of Equus. These are stories of some of them.
A simple drone "accidentally" failed to leave the Badlands hive for the invasion to Canterlot. He was only two weeks old, one of the clutch specifically created to break through the protective shield. Now starving, he's just trying to survive.
A little changeling drone couldn't make it for the big invasion. With the help of other desperate changelings, he avoided pony retribution as long as he could, but in the end, ponies found him. Now alone, he's just trying to survive.
After reaching peace between Equestria and Hive changelings, queen Chrysalis takes two high ranks and a small retinue of drones with her on a trip to an island holiday resort.