Is this the real deal??

All day today ive been experianceing period cramp like pains at work which werent so terrible. But now its 12am and ive been up for over an hour with sharp pains in my back to the point I cant even lay down or sit. They come and go every 10-15 min right now. Am I going into labor or are they Braxton Hicks? I already lost my mucus plug. At my appointment on Tuesday I was 1cm dilated and 100% effaced (compeltely thinned out) and im 38W 2D. This is my first baby so im not sure :/