As previously stated it is more of an emotional decision than a rational one. My dh and I had agreed to one DE cycle (1 fresh and FET's as available). when that cycle failed, the pain of that failure was awful. My dh was done but for me the pain of stopping was much worse than the failures. I did not get over the failure until we started working on a plan to cycle again. I think only you can know when you have had enough.