Hip/leg pain

Raeleigh
When I wake up in the morning it feels almost impossible to move. My calves feel like I've run a mile. if I go to stretch, and stretch to long the muscles feel like a Charlie horse. And my hips/ where my leg connects into my pelvic area kill, sharp pains and feel almost broken... Makes it very hard to move in bed, get out of bed and to walk for the first 5-15 minutes then the rest of the day I feel fine. 
What could be causing this? 
I'm 28 weeks Friday