38+2 with constant period-like cramps

Has anyone experienced this? Yesterday afternoon and evening I had vague period-like cramps that came and went, but they weren't really timeable. Today I have basically had constant cramping all day. I haven't really been having Braxton Hicks so I have nothing to really compare this to. I have also been having lots of aches in my lower back, as well as loose stools. 
I am having a scheduled C section in 5 days, so for as much as I'm ready to have this baby, I kind of hope she holds out until then!!