Good day) At 39 weeks, sometimes there's a pulling sensation in my low…

Good day) At 39 weeks, sometimes there's a pulling sensation in my lower abdomen, the mucus plug hasn't come out yet. But when I walk, it feels like the baby is already ready to pop out himself) It's putting a lot of pressure on the bladder. I had an ultrasound at 36 weeks, everything looked good according to the ultrasound. That's just that they're setting up an appointment for May 30th based on my cycle, but the ultrasound didn't give me a date. Should I have another ultrasound done? First-time mom, scared, maybe something's wrong. Just because they calculated the baby's weight based on a table said it was