AlTA for messaging a girl I like and wishing her luck for her exams?

I (22M) have been chatting with a girl (22F) with whom I've shared some quality time in the past. Recently, she wished me on my birthday, so just out of courtesy, I asked her how she was doing. At one point, she mentioned that she's busy with her exams—she's doing her master's.

She usually replies within a few hours, but this time, things felt a bit different. Over the past few days, we’ve only exchanged 3-4 messages a day, which I find kinda annoying because I feel like it doesn’t take much time to reply back.

Anyway, I wanted to show some support and let her know I care about her and what’s going on in her life, so I wished her luck for her remaining exams ("Anyway, best of luck for the rest of ur exams ✨") while keeping the tone friendly and positive. But she saw my message and didn’t respond.

Now I’m worried I might’ve said something wrong or overstepped. I used 'Anyway' in my text because I was frustrated that she was taking more time than usual to reply, and honestly, it pissed me off a little. So I just wanted to end it politely.

Did I come off as annoying? Or is it possible she’s just busy and didn’t have time to reply? I’m feeling a bit insecure and want to know if I handled this poorly.