Hello, this could be a organised hematoma
, that is collection of blood under the skin more so occurs in the leg since bone is just underneath the skin. If you have no pain on weight bearing on the injured leg then do not bother it will take its own time to dissapear. Do not rub or massage
. If weight bearing on that leg is painful then kindly meet a orthopaedician and take a x-ray to rule out any bony pathology. Thank you, get well soon.