Kel - I still have pain here, specially when DS1 jumps on my thighs the wrong way. I've found my back is playing up again too after a particularly agressive play with Pip

Santosha - if you're going to be climbing stairs, and before it gets any worse, I'd really be going to the doc / pregnancy health professional to get a referral to a physio and get a back support belt (plus some special exercises) to help with the pelvis as your pregnancy progresses. I know how you feel - I was still bushwalking (or rather, bushwaddling!) a week before Pip was born (after his due date even) but with Will, I couldn't even waddle to the bathroom at work at 30 weeks. The best thing though is that all this means that your body has heaps of relaxin which will help with the birth.