Hi, I'm running in Invisible Shoe 6mm Contacts, and have started to experience a bit of pain and some minor swelling on the top of my right foot, between the big toe and the next. Nothing serious enough to make me limp, but definitely noticeable, and I don't want it to get worse. Don't think it's caused by the lace between the toes, as it hits a different area, and I've have no problem there. I'm only doing about 15 mi. weeks now, and have been in minimalist shoes for a few months. I occasionally do from 1-3 miles barefoot, too. Any ideas as to what might be causing this? I'm only worried about a stress fracture, but it seems like soft tissue pain. Thanks!