Well I asked my OB today and she said Acupuncture is perfectly safe at any stage, just go to someone who has experience with preg women!
She has recommended that I can go now for back pain if I like... and that around 35 weeks I could start for deep relaxation and labour prep and then around 39 wks they may start to do some of the pts they use to induce labour... she said that there are many studies that show benefits, she personally is not sure either way but it certainly wont do me any harm....
So i think I will go for it!