back pain = labor?

Melena
Okay so last night around 7 I lost my mucus plug. There's no way it was anything else! Then at about 10 or 11 last night my back started aching pretty bad, but eventually died down enough that I could fall asleep. Now this morning at about 7, my back pain was so bad it woke me up. Since then it comes and goes. It's right around the area where my hip joints are and is dull and constant, but periodically is SHARP and radiates. I just started timing the sharp pain to see if possible it's back labor. Anyone have this with previous kids? Or hear anything about it?