Advice needed!

My boyfriend and I have been together for 3 months now. I know I'm still in the puppy stage, but I feel like he isn't. I always text him and it takes a while for him to respond; sometimes a day! He does work Monday-Saturday. I just wish we spent more time together. How do I bring up something like that to him? Why does it take him forever to respond? I'm the one who always texts first. I just don't know what to do!