Worried, is this normal? 24 weeks pregnant today and?

i have a knotted muscle in my back! Had the doctor's today and she said there wasn't much they can do until it sorts itself out. The pain is quite bad to the point i feel sick. Puttin a cold compress on it helps sometimes but other times there is no helping me :-( Paracetamol sometimes helps, but i'm worried if this could be stressin out my lil one? She was moving around so much today and it kinda worried me, is too much movement normal? and any ideas on how to help unknot the muscle so it doesn't hurt as much? thanks x