Balancing Hope and Disappointment

The most difficult thing for me to find a solution to in dealing with our infertility is finding a way to balance hope and disappointment. Do I allow myself to have hope when there is only a 2% chance of natural conception? By hoping I set myself up for the inevitable disappointment each and every month. Or do I just give up and think it's never going to happen, at least until we have medical intervention. But then I would be without hope. It's quite a conundrum for me.