Opinions?

So, I'm 35w2d and I have experienced Braxton hicks contractions. But yesterday my entire lower back hurt to the point I had to grip something just to stand up (I was at work when this happened) I could barely walk because of it hurting so badly and my hips and legs started going numb. Does this sound more like the baby is laying on my sciatic nerve or could've that been a full contraction. Cause I also had that happen 2 more times but more "bearable" and hour afterwards.