Yes - ALWAYS turn/replace your rotors when you replace your pads.
Mileage will dictate the necessity for turning vs. replacement -- and typically you can only turn/lathe the rotors one time before you reach your minimum rotor thickness.
I forget the specification, but I KNOW it's in the FSM, if you're curious.
Btw: rotors don't "warp" -- vibration and judder when braking are a result of pad material transfer from the brake pads to the rotor surface.
This is commonly referred to as "warping", but it's a tongue-in-cheek term. Literal Rotor WARPING is only achieved in EXTREME overheating situations, like racing or commercial applications.
Removing this material is accomplished by lathing or turning the rotors either on or off the car.
I just replaced the orig. pads @ 70k mi. on my gf's 04, and because of the h-tool (or lack thereof) I simply paid Firestone to turn the rotors ON the car.
These were the orig. rotors, and hadn't been lathed before -- so "turning" was much cheaper than replacement.
Next time will be new rotors. God knows how long the drum pads/rotors will last -- but I'm sure it won't be long.