Do i qualify for free transit

Hello would i need a visa or can i do a free transit if i did LAX--- Shanghai SHA airport--- Tokyo---Hong Kong---flew back to Shanghai but to Shanghai PVG airport and flew back to LAX the same day of arriving to Shanghai but from a different airport Shanghai SHA where i originally arrived from.

the thing is i bought a round trip from LAX to shanghai but would arrive into shanghai from a different airport. idk if that would be a problem

please help