Possessive?

So my boyfriend gets mad when I don't answer his calls or when I hang up on him real fast. I'm in college and I have late night meetings with my sorority and some professors cause it's how the time works out and he says it's cause he's "worried" about me. But he'll call me back to back and text me kinda "getting on to me". Is this controlling or possessive behavior or is he really concerned? What's you all'so opinions and do not be afraid to just straight up say what you think!