What key am I in please?

[Jerome]

You aren't in any specific key. In order to be in a certain key you have to be playing notes of a diatonic scale - you are playing notes of a chromatic scale -and then only some of them. In theory you can have any chord you want behind the notes you are playing as long as those chords contain some of the notes you are playing but it won't sound pretty! The chromatic scale is used for decorative purposes and not usually used for western popular music.