You can see if you go to your profile then click the >> tab then click on Mentions.
I kind of have a problem too, I just tried mentioning someone in my blog so they know I replied back since there's no notification if someone replies to a comment in a blog or if there's a comment in the first place. Anyway, when I tried mentioning them, their name came up as if they weren't mentioned in the first place. Can we only mention once in blogs or something?