Period like cramps

Myranda • 25 SAHM. 3year old daughter and angel baby and baby boy on the way.
I am 39 weeks and have fairly strong period like cramps. The only thing is, they don't seem to be coming in waves like many people describe contraction. They seem to be very constant and other then feeling them in my back as well as my tummy, I have no other labor symptoms. Still haven't noticed losing my plug or anything like that.