Pulmonary Embolism Support Group
By far the most common form of pulmonary embolism is a thromboembolism, which occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs. Symptoms may include difficulty breathing, pain during breathing, and more rarely circulatory instability and death.
This might be very individual, but my personal experience with DVT has always been that if I sat and elevated my leg, the pain would substantially subside and sometimes even go completely away....until I stood up again and it all came whooshing back on me. I've personally never had a cramp feel that way, but I don't know that everyone experiences that type of sensation with a DVT, though.
Maybe try to take some good precautions against cramping, though, like being sure to stretch really well before exercising. To me, that would be the ideal situation - just avoid having both things, if at all possible.