You and Ash both overslept on the day you'll get your first pokemon. Ash was running in his pyjamas while you were dressed normal running to see profeser Oak.

when you both arrived at the lab, there was a crowd of people around Gary, since he already got his pokemon

you and Ash both enter the lab and find profeser Oak, to only find out all the pokemon were already taken,except for a stubborn Pikachu and stubborn shinx. Ash got the pikachu, and you the Shinx.