Preterm labour ?


I’m only 31 weeks, second bub but since yesterday afternoon I’ve been having what feel like menstrual like cramping, cramping I had later in my first pregnancy when I had started dilating etc although I haven’t been having tightenings. Heaps of pelvic pressure though and peeing all the time! Light pain at the top of my belly but idk how to explain it, closer to chest pain rather then belly I think thouhh it’s like just under chest but right up the top of belly and I can’t always feel it it just faintly there. Maybe stretching ? I’ve been getting on and off nausea and just feeling off in general. It’s hard because I’ve read for some people this has been their pre term labour symptoms ? I’ve also just been extremely exhausted but I’m gonna put that down to iron and how far along I am. What were your preterm labor signs ? How did you know? Please no negative comments, I had a hard pregnancy with heart problems and pre-eclampsia last time and was induced at 38 weeks. The cramping was what I experienced and that was it for labour so I’m just unsure 🤷🏼‍♀️ any advice will help ladies xx