37 weeks pregnant and I feel soreness.?

I am 37 weeks pregnant and I have this obv. baby bump, but below my baby bump where it is almost flat, it is very sore. I am planning on asking my doctor on Thrusday, and I;m not too concerned, but I was wondering if it is because the baby is getting ready to drop? I have an office job so I sit a lot, and when i stand it is very sore, and making me waddle, I would like to know if anyone has experienced it, and what you did or what it was, thanks!!