I am scheduled to fly roundtrip EWR-FLL, leaving wed. and returning monday morning. However, i've found out that i will recently will be needing to go to Shanghai for a business trip the same monday morning. My current FLL-EWR flight does not allow for enough time to make the EWR-PVG flight monday morning. If I buy a new ticket from FLL directly to PVG, it will stop over regardless in EWR, so it would be FLL-EWR-PVG. I could leave FLL on sunday night (instead of on my current leisure flight monday morning), have a overnight stopover in EWR, and then make it onto the monday morning EWR-PVG flight. I've called continental to confirm that if i take the first leg of EWR-FLL and call before my return leg to reschedule/cancel my FLL-EWR leg of my roundtrip, it should be ok. However, i've read online about "hidden city" & "throwaway" ticketing and am worried that that this iternary would count. Any thoughts?

Wed: EWR - FLL (original flight)
Sun: FLL - EWR (new flight to shanghai, overnight stopover)
Mon: EWR - PVG (new flight to shanghai, continuation)
FLL - EWR (from original flight, i would call and request to either cancel or change this flight once i landed in FLL wed. evening)