Give him some down time, not only is he anxious about results but also mentally exhausted after exams. Guys come round once their “me time” quota has been satisfied – it’s got nothing to do with you or the relationship, it’s just a basic space need which guys crave after a stressful, tiring event – zone out with video games, meet their guy friends for a quick game or watch their match, drink beer – your boyfriend needs some space to rejuvenate, I am sure he will contact you soon, be supportive and positive, everything will be fine.