thanks for posting your query.
There may be possibility of formation of hematoma
on the inner aspect of right knee and thigh.
Presence of hard large mass suggests the diagnosis.
You should consult with general surgeon/ internal medicine specialist and should go for thorough check up.
generally take 10-14 days for complete recovery.
Hematoma may take longer duration depending on the size.
As you have already defined that present size is less than the size on the day of injury
You can apply thrombophob ointment for faster recovery.
Dr. Mayank Bhargava