Three female doctors allege they have been paid substantially less than their male counterpart in a federal lawsuit filed against Carolinas HealthCare System on Monday. The lawsuit says that a male coworker, who worked as a hospital pediatrician, was paid “substantially more” than the three female doctors for doing the same job. The doctors are suing their Concord employer, the Charlotte-Mecklenburg Hospital Authority, which does business as NorthEast Physician Network, and is an affiliate of Carolinas HealthCare.