You poor thing. I've never been to an osteopath. A friend of mine goes fairly regularly and swear by it! I belive it is kind of a cross between physio and chiro (ie: massage but they will manipulate you if you want) but I could be wrong.
I had some bowen therapy when I was first pg with Flynn. I'm not sure if they can work on you when 'heavily' (not that you are) pg. It did work wonders tho and so gentle.
For pain relief I like the soluble panadine. When I'm not pg neurofen works best for me. Panadol is rubbish.
Hope you get some relief soon.