it may well be the babies position, if the babys spine is running along your spine its ment to be more painfull, a way that you can try to encorurage your baby to turn round is by walking up and down stairs sideways as this rotates the baby. My midwife said that if your in labour and the baby is in this position, they encourage you to walk up and down stairs in the hospital. I have suffered from nasty tailbone pain off and on throughout my pregnancy, even in the early days, it may be that the baby is laying akwardly on a nerve. in which case there isnt a lot you can do about it, just aviod bending the main trunk of your body without using your arms to support you.