Back pain, pelvic pain, abdominal hardness

I'm 33 weeks now with my second baby and this time around I've been having the worse back/pelvic/uterine cramping pain. Went to my OB and she sent me to the hospital to get IV fluids for dehydration. I'm still having pain and my abdomen is like a rock it's so hard. Was wondering if anyone's felt this. I had to stop work early because I can barely walk! To think I have 7 more weeks to go.