I have had pain in that same spot, although I can't say for sure what exercise caused it. Similiar I have had "mystery" pains in my neck, knee, and elbows at one time or another. For the most part the pain went away when I stopped going as heavy as I could, everytime I worked out. Working in light days has really helped the pain and hasn't hurt my gains. Sometimes you gotta check your ego, know what I mean?