With my job I have had over 12 exams over three years. This week is my final exam so I had planned to go for a meal and a few drinks with my girlfriend. These plans were made weeks ago. Yesterday my girlfriend said we'll have to cancel as she can no longer afford it as she is seeing friends this weekend and she's seeing another group of friends the weekends after that. She mentioned the plans have just been made and it's the only time they can all make it. I pointed out she can't make it if she's having to cancel our plans to go. I pointed out celebrating me finishing my exams should be more important to her. She said I was being unreasonable and we could just do it next month. I told her she can see her friends next month instead. I told her I should be a priority and she shouldn't be canceling on me the second anything else comes along. She said I wasn't being fair and it's not often all of her friends can get together but I just pointed out again the celebrating me finishing my exams should be more of a priority to her. She just said again that I wasn't being fair. AITA for expecting her to keep the plans we made?