Aching legs?

Candy

I just found out a few days ago that I'm pg for the 3rd time. I'm almost 36 (on the 16th) and I just seem to be having a rough time already. My legs from my thighs to knees and into my calves are aching. Its more at night but some during the day when I'm resting. I'm not sure if this is a pregnancy thing or not. I dont remember this from my other two pregnancies. The aching is constant but dull. Like its not agonizing or anything but its keeping me up at night because I can't get comfortable. It feels like I've walked a 100 miles and my legs are tired. And they also have a kind of burning sensation? Thanks for any insight.