Hmmm, I'm not sure. I hope for you that's a sign of labor. I have the same problem, but I'm hoping it's constipation...not ready for LO...he must wait.
with my first daughter I was feeling a TON of pressure right before going into full blown labor. Turns out that they were actually contractions. Try timing the pain and see if it comes in any pattern.
Re: Pressure before labor question