Well, without knowing your exact cirumstances, here goes:
Typically, a name change is only done if the person does not already have a Christian name. For example, if your name were Zaphod, you could probably choose a different one. However, it is highly unusual for someone who has a Christian name already (such as yours) to be known in the Church as anything else.
Therefore, this would be a determination between you and your priest as to whether your particular circumstances would warrant a name change.
Hope that helps.
YtterbiumAnalyst (who kept his Christian name at conversion)