I shouldn't count my chickens before they hatch

I know the old expression and I know not to do it. But I did it anyway and the situation did not work out to my advantage. I was supposed to get a promotion as soon as she was able to get it approved. I assumed that I would get it by December so I made a new budget taking into account a modest amount that I thought I would get.

Enter December and my supervisor basically told me that I'm not getting the promotion at all and my raise is now going to be at the end of March. She also gave me a semi-bad review so I'm not expecting much in the way of the raise. Meanwhile the new amount was in my budget making me short every month. Luckily I'm able to meet that shortfall but it's not easy.

Lesson learned. Now to not do it again.