Should I contact him, or is it too clingy?

This guy and I have had a somewhat serious, monogamous thing for about two months. He said his phone wasn't working, so he wouldn't be able to contact me for a while but would contact me when his phone was working again. It's been about a week and I've been missing him. I have his email, would emailing him be too clingy? I want to avoid that so I do not suffocate him, because I like him a LOT but don't want to come on too strong. In short: how much is too much??