aching crampy legs

anyone else have achy crampy legs? it feels worst in the lower parts of my legs like my shins and calves but sometimes my whole leg aches. then I get a lot of tightness and Charlie horse type cramping at night. I'm 22 weeks and im up on my feet a lot as I'm a full time nurse and mommy of a 2 year old. Just wondering if anyone else is experiencing this ... I know about the increased risk of dvt but I reay don't think that's the problem. anyone have any solutions?