When doing dips, recently I get a pain down on the inner portion of one pec or the other and a strange feeling right down the middle (sternum). I asked that my form be checked by the instructor, he said that there weren't any problems that he could see. Only advice was switching to another exercise. I did bench today, and no issues with my chest (Although I felt the burn in my delts like they haven't been touched in ages).
Second I get a subtle pain in my left forearm that occurs when I grip onto something and it only starts to happen about half way through my routine. If at the end of my routine I want to curl, the pain, palms up, is not something I can do. Palms to the side (Hammer curls) and I can get through, although not as comfortably as I do with my right forearm that has no pain.
No real advice from the gym trainers. I asked if this is something they would recommend I see a doctor about and they said that I'd probably be told to stay away from heavy lifting and send me home with some painkillers.