This is what two consecutive weeks of ratings gains would get you — NBC has ordered two more episodes of midseason drama Chicago P.D., bringing the total to 15 episodes. It is unusual for midseason shows to get extra episodes as they often had already wrapped production by the time they begin airing but Chicago Fire spinoff started filming relatively late because its producers had to get Season 2 of the mothership series going first. Chicago P.D. was not scheduled to wrap its original 13-episode order until Feb. 20 and will now remain in production for two more episodes. Through its first four weeks, the freshman has averaged a 1.7 rating in 18-49 and 6.8 million viewers in Live+same day. It became the first new drama on the Big 4 this season to generate ratings increases with two of its first three telecasts after the premiere.