Sharp pain on bottom of foot - PF? Something else? (Read 42 times)

Hi all, I've been having a weird pain on the bottom of my right foot and I'm having trouble figuring out what it is. It's a very sharp pain that feels like a cross between a bee sting and a pinched nerve. I made a little diagram to show where it's happening: http://i.imgur.com/Ex29CoD.jpg

Usually it happens a few miles into a run, moreso when I'm running faster, like during a tempo run. It noticeably impacts my stride if I try to keep going, as I have to compensate by adopting a weird footstrike where I'm basically running on the outside of my foot. If I put any pressure on the problem area during a flare-up, it's intensely painful - it feels almost like something in my foot is going to snap. I've had to cut a couple of workouts short as a result. The thing is that it doesn't bother me during every run, just sometimes, and it doesn't tend to bother me when I'm just walking around. I do remember experiencing something similar as a kid, like 15 years ago, when I was playing a lot of soccer. But this is the first time I've dealt with it as a runner. I don't think it's PF from what I've read, but almost everything on the web about bottom of foot pain is about PF. Any ideas? Thanks.