I've been having a consistent pain that started about three weeks ago in my left calf. It started as what felt like a Charley horse, and has been consistently throbbing. I also have been short of breath and really tired. The pain goes into the foot as well. My veins have been protruding a bit more in the ankle and up to the thigh. Upon waking I can't put weight on it until I work it out. Web sources are freaking me out. Should I be concerned?