early signs of labour?

So since Monday when I turned 37 weeks I've been having really bad stomach cramps, like when you've eaten a really hot curry kind of cramps lol! They have been very irregular and sometimes haven't happened for hours on end, I've not been able to sleep as no matter how I lay it's so uncomfortable. I've also been getting out of bed for a wee at least once every two hours through the nights and then last night the  diarrhoea started. I've also noticed my appetite seems to have gone, as I've only eaten about 1 meal a day since Monday. Does anyone know if this sounds like labour is imminent or has anyone else had anything like this?