Terrible back ache!

[xfingerscrossedx]

Hi all,

I'm only 24 weeks, but suffering from the most horrific back ache. It's really low down and when I sit down in the wrong position, it actually makes my eyes water. Would normally have a hot bath and take some co-codamol, but this is obviously out of the question. I'm a teacher, so either on my feet or sitting marking all day and evening.

Any magic tips??

Is it all the time or only when you move a certain way or spend too much time in one position? Can you make it go away at all?