thanks for your query
i can feel your concerns
i would like to know if you have any history of bleeding or bruising spontanously or at any other site
Moreover do you have any family history of blood disorder?
if no other issue,then usually it is due to faulty technique.and need not to worry.it will resolve in few days.
However if persist then you need to see your doctor and you may need some blood tests to rule out low platelet count
or any bleeding disorder
i am available for your help