Please help

I was up & down all night with bad back pain.. this morning I finally decided to get up around 5 and I took Tylenol 2 hours ago.. still no relief. It hurts really bad, and shoots down my leg. I feel my belly get tight also. Baby isn't moving AS MUCH although she still moves every now & then . I had a membrane sweep yesterday. Lost bloody show before the sweep. And a little more after. I'm 39 weeks today, & Dr expects me to have a baby this weekend... What is this pain?! Do I need to call l&d? This is my 2nd child.