Oh how I feel for you!
This has been an issue over the past 20 weeks. I started feeling pressure at 12 weeks, no kidding... I've measured ahead by three weeks twice now. That baby is very briefly up in my ribs, but the moment I stand or sit down too long, down it goes with gravity! I've had my cervix checked several times, and it's all good, no signs of dilation or effacement, but the pressure is starting to drive me crazy. Laying down seems to be the only thing that works, so far. Good luck to you! :)