Back labor or nerve pain?

So I keep losing my mucus plug and baby is super low for a few weeks now I woke up the other night with really bad back pain and I thought maybe I was sleeping weird so I got up and when I stood up it got so much worse!! I laid on the floor in pain and it was coming in waves and made me sick to my stomach and start shaking. Does this sound like having back labor contractions or maybe she was laying on a nerve wrong? It happened inconsistently throughout that night and kept coming in waves and barely got a break between them but ended up getting less and less painful over the hours.