Your question is not clear. Why do you want a DNA test? who is it that you wish to have the test - your boyfriend or the true biological father? Did anyone sign a Voluntary Acknowledgment of Paternity? if your boyfriend signed it he has only a limited time to rescind his signature. These are not forms to be signed lightly as they have lifelong consequences. Harm may already have been done. You should seek the services of an experienced family law practitioner to try to straighten out this mess.
Assuming no Voluntary Acknowledgement of Paternity (VAP) was signed, the correct procedure for you would be to file a Petition to Establish the Existance of the Father and Daughter Relationship with the proper Summons. Thereafter, you would have the alleged father served. If he feels he is not the father he could request a DNA test. However, if there was a VAP signed it would become conclusive after a period of time. I would suggest you consult with a family law attorney about this issue.