worries about the transfer in Beijing airport

my route is La Guardia-Chicago-BJ-Manila. I have different airlines form Laguardia to BJ is American airlines and BJ to manila is Philippine Airlines. I am really worried about my baggage because i dont know if need to get it and transfer to connecting flights. Or i will just get it in my last destination eventhough I bave different airlines. what if my baggage did not reach my destination. One thing i am worried of is i have only 3 hours layover in PEK and i need to transfer terminals. I think asking the people their about the direction take me so long because most of them cant speak in english. Just what happened to me in Shanghai. that was the reason why i was trapped there for 24 hours.