Hi all I was getting dressed this morning and all of a sudden my lower back stiffened up, almost like a back cramp. I tried to stretch it out to no avail and whenever I walk, it's more painful. Tried the yoga ball and it feels more painful sat in that position. It keeps coming and going, maybe a spasm/stiffening every 5-10 minutes and then just feels achey and painful in between. I'm not sure if I should call the midwife assessment unit or if it's just that I've pulled my back. Has anyone else experienced this? I've googled and of course it says it can be a sign of preterm labour but my first born was only a week early so I feel 8 weeks early is very early!