My back labor personally didn't feel like that so I'm not quite sure.
It could be that, I'm not sure. It happens randomly sometimes, & the other night it was coming in intervals of about every 40 secs for over an hr & I thought it could possibly be back labor but I have no idea, I'm a ftm.
Sciatic nerve? I know my daughter was on mine on my birthday and I couldn't do anything without it hurting.