Most Helpful Guy
No, you should not be upset with him. If he has to work, he has to work, he can't help that. And he did warn you it would happen, and he does try to see you. So I would think he should get a pass for sure.
However, your reaction may be something you want to think about. If you are upset about this happening, and it is possible that it could be happening a lot, the relationship may be in for a rocky road. It may be the case that his availability does not match your specific needs in a relationship. That doesn't mean you are wrong, or he is wrong, just that things do not line up right. You have to think about how you feel when this has only happened the once, and then extrapolate that out to how you will feel if it has happened to you 20 times. Or if he has had to work late after you spent all day making a nice romantic dinner. Think about how you will be able to handle those kind of situations. Especially once the honeymoon phase wears off.
It will be challenging, for sure. But if you think you can handle it, you need to make sure that cases like this don't get to you. It won't be the last time it happens, he has already mentioned that.
Also consider the frequency. Maybe it will only happen once every two or three months. And you would be ok with that. Maybe it will happen every two weeks, and you won't be ok with that. Don't worry about it right now, but watch it, see the frequency, and consider your feelings and your needs.