calf, arch, knee pain

So today i went on my long easy run, which is only about 6 miles.  1 mile into it, i can feel my shin start to hurt.  2 miles into it, the pain was easing up my leg, eventually reaching my knee.  The pain was also in the shin, but felt a little different than shin splints.  My left knee then started aching, and found it was worse when i ran downhill due to my feet making a harder impact.  3 miles into the run, my right arch started aching (flat footed).  After about 3.5 miles, i decided to open up my stride and increase the speed in hopes to be lighter on my feet. BTW before this, i was going at a really slow easy pace.  After i opened up the stride, i noticed that my legs felt better the faster i went.

But all through the run, it seems no matter what i did, my left calf was in pain.  It felt like i had done too many calf raises or something.  From what i can tell, my stride is pretty even, but my left calf is soooooo much more sore than my right calf.  My left hamstring and quad are also much more sore than my right, but not as bad as the calves.  In fact, my right hammy/quad aren't even sore.  My arches are also a bit sore.

The same thing happened last week with my left leg.  I did a track workout and my left leg was retarded sore.  It was so sore, that i couldn't even bike two days afterward. 

Why is this happening all of a sudden?  For the record... my left calf is 1 inch smaller in circumference than my right.  But as far as i can tell, my left and right thighs are the same size.