throbbing/pulsating back pain

Olichka • Due on June 29 with a girl! 💖
I'm 35w +4 and I keep getting this throbbing or pulsating pain along my spine.  Most of the time it happens right after I've changed positions, from standing to lying or from standing to crouching, but sometimes it just happens when I'm sitting there not doing anything. 
Someone told me it sounds like back labor but since it's inconsistent I think it may be false labor. Does anyone else get back contractions like this?