I echo what Dee said but it may also be your bladder cramping. Sometimes if I’m desperate and then go I get that even before pregnancy but if you are concerned always call triage x
@Stephanie I had this aswell and it turned out I was constipated🙃😂 it’s scary because you never know if its serious or something silly , hopefully your feeling better !
Monitor if the pain gets worse, I had tightening and similar to you at 36+3 , took 2 paracetamol and slept it went away by the morning, if it gets stronger or doesn’t go away by moving I’d phone triage see what they say x