Any signs for shortening cervix?

I'm 26+2 with di di twins. At my last appt they got me a little stressed saying how we needed to schedule my section at the next appt and talking about my cervix and if I'm feeling pressure. Well last night I was really uncomfortable and a couple times felt like baby a was wedged in my pelvis and couldn't get relief until I moved around a little. Today I feel some shooting pains and soreness, I've had increasing heaviness and pressure that I assumed was just normal for starting to get bigger. I also have a vulvar vericose vein so that makes everything kinda feel like it's just gonna fall out. Does anyone with a confirmed shortening cervix have any advice for how it felt or signs. I don't want to drag my son to the dr for a long wait if everything is fine.