Is this something serious?

My 3 year old came home from part day preschool, accusing a little boy of touching her with a doctor needle multiple times. This isnt the first time shes mentioned this little boys name. She has told me of prior incidences, where this little boy has laid on her and/or kissed her. Should I be concerned, and have a sit down with the pre-school director? Or chop it up to kids 'Play Dr'?