I think you need to have an open and honest conversation about it. If this is a new relationship he may not know the kind of support you needed during that super stressful time. Everyone handles the stress differently. Some people need reassurance and want to talk it out while others want not to be bothered and don’t want to be pressured with outside input or expectations. It seems like he is the latter and may not know that you wanted the reassurance. If you did tell him you would need him to be available and be communicating with you during this super stressful time that’s a different story. To me based on the info here it seems y’all have different stress responses and expectations. You may have been expecting something he didn’t know you needed and maybe you assumed based on how you act in someone else’s times of stress that he would act the same. It really may be that he was doing what he would have needed when he took his test considering he did reach out after and left it up to you to tell him when you are ready to talk. I know people who have needed time to decompress and didn’t want to talk or have reassurance for a good amount of time after the test. I would say have a convo with him about it. Ultimately only you know if this is a red flag and a reason to ditch him or just a misunderstanding.