Injury?

This training cycle has been a bit rough for me.  I've had an injury that keeps cropping back up (or never fully heals).  It's a pain right in the crease of my leg, perhaps a groin strain?  It might be my hip flexor though, I'm not sure.  It usually acts up when I'm pushing myself hard on a run (typically during speed work).  It starts as just a little twinge but then if I continue to run it escalates to the point where I have to stop running. 

I've spent the past few days at Disneyland with my family and we did a lot of walking.  I realized that I don't have a good pair of walking shoes so I just wore my Saucony Kinvaras which aren't a really supportive shoe.  Plus Evan was teething and had a cold and wanted to be carried whenever we were waiting in line.  I think the combo of the two aggravated it more as I started feeling the pain all of the time, even when I wasn't running. 

I managed to run 3 miles yesterday and I did feel it but the pain didn't get bad enough that I had to stop running.  I'm supposed to run 13 miles tomorrow but I don't think that's wise.  I've made an appointment to see my doctor on Monday.  Hoping just a few days of rest will help.  With the half marathon 3 weeks away I really don't want to miss out on too many more training days.