Husband on vacation but not talking to us

My husband went on vacation in another state with his boss and coworkers for 6 days. We have 2 kids under 2 and it's the first time I've been alone with them this long by myself. He really wanted to go so I said okay. It's been 3 days and he hasn't been calling or messaging us. When I message him he barely responds and always says he's busy. I'm pretty upset. My 2 year old keeps asking where he is but he doesn't even make the time to call us and check in on us. I even told him how its making us feel and he said ok he'd do better but it's worse because I only heard from him once today. Do I have a right to be upset??