Self seeded lavender in old pot (Westbury Fields BS9)

This lavender plant self seeded into an old pot on the patio. Can't recall what colour the flowers are, most likely a blue of some kind as the lavenders close to it are all blueish. Probably about 4-5" high at the moment. Lovely plant but I have plently of lavenders already.
The pot is old and breaking apart and there is very little soil in the pot, so it would probably benefit from being repotted or planted out somewhere.