...(at least the full sensitivity that they *used* to describe as the target for the project) for 2 months and they have detected nothing.

To me this means that either:

1) sensitivity of the instrument is mis-calculated.
2) wavelength and/or amplitude of gravity waves are different from what we expect.
3) events causing gravity waves are not as common as we thought.
4) no such thing as gravity waves.
5) selected a stunningly unlucky period of time to come online - no incidents to detect.

Should we start a pool?

In any case, it is critically important to figure out what's up. All the other gravity wave projects in the pipe may be barking up the wrong tree, depending on cases.