Am I right to be upset?

My fiancé and I have been together for 5 years and are expecting our first child together. We had plans to go to the zoo today because it was the first beautiful/warm day in awhile that we both had off work. Well when I woke up he told me we can’t go anymore but wouldn’t give me a reason. He said he had to go take care of something and we could get dinner together tonight.

He left around noon and I stayed home all day cleaning and then watching some TV. I texted him but never got a text back or even a call. He finally walked through the door at almost 10pm after I’d already made myself dinner.

I asked him where he was and he said he was visiting his ex who he was with for 2 years before us. He said she texted him and was sick with a cold and she needed someone to bring her chicken noodle soup.

He said they’re just friends and broke up because there was no chemistry between them, but I’m really upset that he did this. He acts like I have no reason to be upset and told me that if I act psycho over this then I can sleep on the couch tonight because he doesn’t want to sleep near me if I don’t trust him.

Would you be upset?