First Broken Promise

So I'm catching up a little bit. I was only signed up to work an 8 hour shift, today and promised Jackson to pick him up at school. Well, of course, we were short staffed and they needed a nurse to taking a vented baby which a lot of the new nurses can't do so I agreed to stay for a full 12 hour shift for double time. Seriously, how do you resist that? I called Eric and told him to explain why I had to break my promise. When Eric picked him up at school, he said, "What are you doing here? Where's Mom?" After the explanation he understood, but I don't think I have ever felt so bad.