<human>: Over the past couple weeks, I've noticed she's becoming more distant. Every time I try to set up a date or just hang out, something comes up, and she is too busy. Most notably, today is her birthday, and we had plans. However, she flaked on me last minute with a poor excuse of "I have to run some errands, I don't know how long it is going to take." I asked her to tell me when "she was finished" so I could spend time with her, but I haven't heard from her all day.

Two weeks ago, we had an argument over my grades. I'm not doing well in school and she was concerned about it, and my future. We haven't really talked about our future together, but I'm sure she's got that in mind. I have a feeling this is what is causing her to distance herself from me.

Do I give her the space she seems to want, or should I do something about it? Should I be bracing myself for being dumped?

Can you summarize the given text in a few sentences?
<bot>: Girlfriend upset with my grades, distancing herself from me. Today is her birthday, won't let me spend time with her. What do I do?