He obviously really likes you, but I do think that sometimes called 'a little too much' in a relationship. All relationships need some form of space. It's not healthy to be constantly calling you until you answer, that can become very annoying. Have you tried talking to him? Tell him how you feel and see if he backs off a little. I understand the first stages of a relationship are exciting and you usually want to spend as much time with that person as possible, but there is a limit to everything in life. Talk to him and tell him how you feel, if he doesn't change, you may have to make a hard decision. Eventually what he's doing will just annoy you more and you will end up disliking him for it. Some woman love that kind of attention but every person is different. It's not a bad thing, but you have to be honest with yourself and with him. If you don't stop him now it can only get worse.
ps im posting your que on my site kristinnicole if you have any further que please don't hesitate to ask.