Was I right to call him out on this?

So, I have been dating this guy for two months. We're exclusive and see each other a couple of times a week. We both have pretty high pressure jobs although his is probably a bit higher pressure than mine. I've noticed that he has been subtly canceling on me saying he's tired, or needs to study (he's applying to grad school), or he just wants to call it an early night. This happens probably once or twice a week and there's usually a reschedule involved but I really feel like it is very inconsiderate as I bend my schedule to him. It happened again tonight so I brought it up and asked if it was really that he was busy or if it had something to do with me/not wanting to see me so frequently. He told me that I wasn't being fair or understanding of how busy he was and pulled the "we've only been dating two months" card. I said it had nothing to do with that and he wasn't being fair to me or my schedule. I'm not trying to force him to spend time with me but be a little more considerate, am I right?!