All of these are interchangeable EXCEPT clone. A clone usually refers to a scientifically generated duplicate of an animal or a human as opposed to just someone who looks like you.

Doppelgänger, double and lookalike are all interchangeable because they suggest strong similarities but also suggest they are not identical. Clone means something is literally identical in every single way, and there are no differences. Clone could be used to mean the same thing, when we use it as a simile. So it would make sense to say any of the above, or, “they ARE LIKE my clone.” Hope this makes sense. Feel free to message if you have any other questions