Awful back pain 34 weeks

[Chester6]

I'm 34 weeks pregnant and this afternoon I've suddenly developed a really horrendous pain in my lower back/buttock on my left side. It is agony to put pressure on it. I have been feeling uncomfortable lying on my side at night and wonder if I've been sleeping funnily. I'm so nervous in case it doesn't go away as I am struggling to even hobble to the bathroom. Would this be sciatica or does anyone know what else it could be/have any advice? Many thanks

[Bakingmad001]

Hi. This post is really old & I just wondered did you ever find the cause?