Cant make FaceTime calls with my mac air

I got a new macbook (my first one actually) but I can't seem to make FaceTime calls with it ): it'll just keep ringing and ringing but nothing! When i called my boyfriend on my phone he said he got no calls from FaceTime what so ever :/ And i have no idea why! Can anymore please help me out? My mac & my phone are both on the latest software.