Welcome to HCM.
This is blood leaking from the vain in under the skin. A so called hematoma
. It will take a few days to clear up like any other bruise
, taking some Arneca may help to speed up the recovery. Your rapid pulse and faint feeling may be due to the relative lower volume of blood you now have. This generally rectifies within 6-8 hours. If it perseveres please consult a doctor. Hematoma 's may occur with puncture of the blood vessel , this does not meen it will happen every time. Applying pressure after removal of the needle will help to prevent it. I trust this is helpful.