I know that Pichu can't breed, but this is a Ditto. Is it different??
No, you can't breed a Pichu with Ditto or any Pokemon.
Pichu is a baby Pokemon, and no baby Pokemon can breed, even with Ditto.
If you want a Pichu, breed a Pikachu; it will still hatch into a Pichu.
EDIT: also, trading makes no difference in this scenario.
How to change your username
How to add a user avatar
Why was my post hidden?
Flags vs Downvotes
Official PokemonDb League
Type a Pokemon name, type, move or ability to see instant results.