I think it's pretty standard to get a sore pelvis towards the end of the pregnancy although I can't really remember when mine started. I definitely have it now though Actually Shereejoy actually described it aptly as a feeling like you have been riding a horse!!

If you are concerned about anything though see your doctor or midwife, because I had a friend whose pelvis was actually misaligned while she was pregnant... her joints were really loose that she wouldn't be able to walk sometimes!