sudden extremely achy legs. cause for concern?

hello all,

this is my first small pregnancy panic. tonight my legs are unbelievably achy. before bed my feet were hurting like normal (Im nearly 28weeks and had a busy day) I went to sleep fine and normally but woke up at 2 am because my legs are aching terribly from the knees down! I have been active and athletic my whole life and have had my fair share of aches and pains... but this is bad enough to concern me. :( it feels relative to acid in the legs immediately after a long run, but much stronger. Ive been up for hours now looking for a little relief. ive tried keeping them cool, keeping them warm nothing is helping. Im drinking a lot of water and ate a banana a while ago. they dont look red or swolen or anything. has anybody else experienced this?!