Been dating for 4 months. Isn't it a little soon for him to stop trying?

The man I've been seeing for the last four months (exclusively for three months) has recently stopped calling and I barely get a text message. We see each other often-a few times a week-but I think he should still call me on the days we aren't together, right? When we are together it's great. He's gentlemanly, affectionate and it's obvious he's glad to be with me but I'm just confused as to why he doesn't want to talk when we aren't together. I've asked him about it and he says he doesn't like talking on the phone but in the beginning he had no problem calling me if I didn't call him first or texting me. But now it's pretty much stopped and I'm the one doing all the calling. Am I making something out of nothing or does this seem weird to anyone else?