Should i get an attorney?

I got a letter from the child support services in my area to come and resolve the matter without a court hearing, is it advisable to get an attorney?

PS I have totally supported my son since birth(6yrs lived with me), and the mom practically for the past 8 years.

Things have been rocky for the past 3 years and i finally called it quits 2 months ago ( mind you she stayed with me and i paid for the rent& food & utilities except her long dist phone calls). Now with out consulting me she went and filled for support. Any advise?!