Terminated immediately after giving 2 weeks’ notice

I sent in my letter of resignation today, and my boss called my cell phone after work hours that the termination was effective immediately. I asked (in a professional way) if it was something I’d done and she said no, we’re just a small organization, but she sounded rather angry in tone.

What are my rights as this was an at-will position? Should I file for unemployment? What reason would she have for doing this?

Also, what does this mean for potential future jobs? I have one lined up while I’m in school, part time, but obviously when I graduate I’ll need to apply for new jobs in my field. I’m assuming this means I can’t use her as a reference, but I worked there for years and felt (and she seemed to feel) that overall I did really well there. If an application asks “have you ever been terminated?” can I still put no? I mean, I never would have been had I not decided to leave. I’m at a loss here.

TIA!

Update::: they offered to pay me for the 2 weeks!! So now I’m not worried about it at all (kind of happy actually 😂) looks like I’m taking a 2 week paid vacation!