Texting...

So me and my boyfriend don't live very close to each other, however we typically talk every day and make an effort to see each other at least once a week. But lately he doesn't seem like he wants to talk, I mean when we hang out its fine, but over text he seems kinda distant and short with his answers like he doesn't really wanna talk.. Is this normal? Sorry I'm kinda new to this whole serious relationship thing?