TENS machine for backpain during pregnancy

[MrsHarry]

Has anyone used a TENS machine for backpain, rather than just labour? I am 23 weeks and have severe pain at the mo.....trying various remedies including massage and exercises but thought I'd try a TENS machine as well.
Bought a maternity one in Boots which says it's for labour pain, pregnancy back pain and toning abs after birth. Says that you can use it after 12 wks. It's been pretty helpful so far.
However the Mothercare catalogue says you shouldn't use one during first 26 wks, and I've just seen a website which says not before 37 wks!! Help!!
Have just seen my doc today and she's trying to get emergency physio appointment for me but I forgot to ask her about the TENS....
Anyone have any advice or experience? Thanks

Now just read on a site about SPD that shouldn't use TENS in early pregnancy as not enough medical research done about it. Now I'm worried!
Surely Boots should know about this??

i'd go with a doctor's/consultant's advice rather than Boots myself. Better to be safe.

I went to hospital class. The physio says you should not use a tens machine before 37 weeks or it could bring labour on. Go to a physiotherapy class and learn good posture, it helped with my back pain and pelvis pain. I had back problem before pregnant and I know that massage is a temporary fix, creams too, you need to do exercise and there are some suitable for pregnant women.