I'm due the same day also and my son is dropped now but I've had some major back pain also
You can lose your plug well in labor . I'm due the same day as well ! I'm having back pain as well at night and this is just getting your body prepared for labor ! But he'll start dropping soon !!
Is this your 1st baby? 2nd babies don't usually drop until the start of labor. Sorry, no way to tell! Some mama's have no signs then go into quick labor, others show signs. Just be patient and hang in there - you can't be pregnant forever!