I’m confused, am I wrong for that? is he upset? I don’t know what to do now?

I told my boyfriend I’ll be away from him for about 3 days because I’ll be working like crazy and so I can get prepared for my exam in nursing school. I call him my sweet baby and everything and the only response I got from him was “ okay baby. knock it out.” I asked him how his day was and that’ll I’ll still be available to him but I’ll be working crazy hours. He hasn’t responded to me for almost 2 hours.
I’m confused, am I wrong for that? is he upset? I don’t know what to do now?
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