Right!
To add the stray capacitance of the terminals and PCB tracks, the external capacitors can be approximated with: C1=C2=(CL-CS)·2, where CL is the load capacitance of the crystal given in the datasheet, and CS is the stray capacitance (3..5 pF or even higher, depending on your PCB design and crystal size).
For best results, start with this calculated values and than measure the resulting frequency and adjust the capacitors accordingly.
Good luck!
