Can someone tell me what preterm labor feels like so I can look out for signs

I’ve been having pressure around my pelvis and under my stomach (I’m plus size) I’ve been feeling off today and I think my stomach dropped recently I was comparing pictures of my stomach before and after of today (13th) and the 11th and 8th of September and you can see a big difference I’ve also noticed a decrease in movement which is really odd since my little one loves to kick and move around I’ve also been having this weird back pain and I’m just worried at this point I’m like 31 weeks I’ll be 32 weeks in 2 days and my baby is already on the small side so I’m really worried and I potentially might not have a ride on an appointment I need to see but if I can get enough advice to look out for and if I’m actually starting to show signs I’ll be able to find someone since where I live there’s no where that does delivery or deals with pregnancies so I’d have to go a few hours distant