bad cramps at 17 weeks??

Immie
I'm having some bad cramps. It hurts to stand and sit up, it only goes away when I lay down. 
I do feel sick, cold and very tired. 
I'm 17 weeks and I feel baby moving around.  
I've been more active than usual today so I don't know if that has anything to do with it. It's mostly cramping on my left side.