Possible early labor?

I'm 35w3d and have been having dull/achy period-like cramping and lower back pain that is pretty constant but not completely unbearable for the last 4-5 hours. Also haven't felt like really eating today and just don't feel right. 
     This is my first pregnancy and I have to have a c-section. So just curious as to if I should be concerned by any of this and call L&D or not? I'm about an hour and a half from my hospital as well. Any insight or suggestions would be very helpful.