Should i worry about preterm labor?

Okay im having afew things going on. I havent been checked at the dr yet and Im 35 weeks. I know baby has dropped, having nausea just starting last night, constant odd back pain, and mucus type discharge that to me seems like it could be my mucus plug. I am on baby number three and my water broke with my first with no contractions until pitocin at the hospital. Im just worried about going into preterm labor and if my water breaks no way of stopping that. Baby also has pretty well stopped moving. She used to kick and move non stop and now just a couple times a day. Should i be worried about this at all. I just feel funny today a little lightheaded couldnt sleep at all last night been sick and sore. Sorry for the recap I know Im not like sick from a bug doesnt feel like that at all and Ive gotten over a cold and know its not that either. Just some advice wonder if i should call the Dr next week or maybe the answer service tonight or if its just all in my head.