Yes if he truly has things going on he may truly be busy and just needs to find time to talk to you. Give him at least a week and then ask him when you can talk about things or should you just let things be as they are. Don't jump to conclusion right now he may truly have alot of things on his plate at this time. Try to be understanding and patient until you can talk to him.
See if he says anything or if you even see him out, either way you need answers or closure or you will always wonder why and what happened to change his mind. Make sure he hasn't move on to someone else without telling you it will make it even harder to get passed this and leave you wondering what you did wrong when in all actuality you did nothing wrong and it may just be a hang up he has. Just wait some time but don't wait too long for him to give you answers if he doesn't give you an answer in two weeks I would start the process of moving passed this and not looking back if he didn't have just a little bit of time to see if you were okay after your surgery then he is proving not to be a person you can rely on to be there for you through the good and bad times. If he does approach you then hear him out and see if he has a good enough reason as to why the cold shoulder, then make your decision as to whether to stay or move on.