Hi all! I’m 35+2, first baby so this is all brand new and I have nothing to compare it to. I am a qualified nurse but hopeless when it comes to my own body 

I’ve had a bit of an upset tummy for the past few nights, with loose stool and bowel cramps. Baby’s head is also very low in my pelvis and I’m getting lightning crotch several times a day. Haven’t noticed any abdominal tightening, and no increased discharge or fluid leakage. I did, however, have some lower back and upper thigh pain very similar to what I would have during my period last night, had a bath and it seemed to ease enough for me to fall asleep. This morning I’m back to feeling like I need to poo urgently and having some bowel cramping again. I do have IBS but it’s been well-behaved for most of my pregnancy.
Does this sound like it could be my body getting ready to labour, or could I just have an upset tum? I did have a Chinese the night all this started, which was a bit greasy. My midwife isn’t the easiest to get hold of, and I don’t really want to go and spend hours in maternity triage unless I have good reason to. Any advice please? 