Been there, done that, and as some say....got the t-shirt. Just keep at it and use the extra time to study and you will be fine. I actually like my checkrides getting cancelled a few times because I feel more ready and less nervous. Don't ask my why or how, that is just how it works for me. Good luck when it does happen.
Doesn't it just suck? You get all ready to go, and then some random weather blows through and you're like, not again! Or a maintenance squawk. Or you get to the plane, and then you're like, oh, crap, can't take this plane out because of blah, blah, blah.
Whoever said if it's not one thing, it's another was right!