Hi, Thanks for using HCM.
Small lump could be a blood collection under skin( hematoma
) that will get absorbed slowly.
You can take anti inflammatory medication to reduce swelling and pain.
If the injured area is warm to touch/ pus getting collected, there could be chances of infection, you need antibiotic, pus should be removed under aseptic condition and dressing of wound needs to be done.
Hope I answered your question. Consult your doctor for further examination and management.
Feel free to ask me if you have any further queries.
Wish you good health. Take care.