Ow. Generally when you call the hospital, they want to know if the pain is coming in waves...they'll want to know about bowel movements (for example, the diarrhoea probably means you're not constipated, though I suppose it could be wind, or gastro), they'll want to know if you've felt bub move.

To me, the hard tummy, back pain, nausea, slight cramping sounds a bit like labour...but frustratingly, it also sounds like other things like wind or gastro or Braxton Hicks', and they'll probably just tell you to wait. No harm in calling the hospital though, but yeah...it's annoying but you'll probably just have to wait and see if and how things progress. Hope it's labour over gastro though! xo