what could this be? 😬

So I'm 31 weeks and I've been having a lot of pelvic and vaginal pressure that hurts pretty bad. I've been having diarrhea for the past day or two just constantly all day and at my last ultrasound they said my son was already turned and deep in my pelvis. Could this be pre term labor? I feel silly even thinking that but I've read on here about people with the same symptoms and they ended up having their baby relatively soon after that. I just want to be sure I don't need to call my doctor