lagguge that we bring and pass china enroute to another international country

me and my wife are coming from the U.S.A and traveling to our birth place the Philippines. Enroute to The Philippines we have to go to China and join a tour group for 7 days . we are carrying 3 lagguage 50 lbs. each cause that is the weight limit for international flight . while we are in china for the tour I think we have to travel by domestic plane inside china to Shanghai . do we have a problem in our domestic flight, since our ticket destination is Philippines? do we have to pay extra baggage since we are allowed to bring 200lbs instead of150lbs that we carrying ?