Not happy to see me?

I am on call for work this week and we get off at 3 pm when on call so we can be ready to take emergency calls at 4 pm. I was excited about getting out of work a little early and picking up Christopher for some extra mommy and son time. So I get there at 3:30 and they were about to head outside, he sees me and breaks down in tears. He was oh so not happy to see me. Man, so glad I wanted to spend extra time with him. He did not want to go home with me. So I left him for a few minutes and went over to Trader Joes, then went back at 4. I really know better than to feel hurt, but it did hurt my feelings just a little. I picked him up early again today. No tears, but I did get an upset, “Why do you always have to do that, picking me up early?” He asked if tomorrow I would please not pick him up early. So I guess I get some me time instead. I can at least be happy that he enjoys his time in after school care, right?!?!