How do you know things are right?

Well.. Things been going good lately with my bf and I and yesterday we went to themovies and grabbed something to eat... If it tmi than sorry but we've been having the most incredible ever and now today I asked him could I see him later on before he go to sleep he said no I just wanna chill not in a bad sense of way ... Then I called like three times but he didn't answer.. Tell me ladies am I getting the wrong impression or does he just want his own space? O believe in my heart that he loves me but I need to know if he just need space or not?? Idk what to do .. I can trust him but I just wanna know does it have to be like this