You can try the attached circuit.
The 32khz watch crystals are provided for a specific load capacitance, usually a single capacitor connected to the oscillator's input against the gnd. The typical capacitance is 6pF or 12.5pF - you have to check the datasheet of the crystal. Not sure the loading with 2x18pF (those basically connected in series give you 9pF, plus stray capacitance) will give you good results when the crystal is intended ie. for 6pF, though.