Jojo, you can loose your plug sometimes weeks before labour begins. However, given that you are already due you won't be waiting that long

Your plug comes out as a result of your cervix thinning out/effacing and from dilating a little. Your cervix may feel a little tender as it is opening up which is why the movements from bub may be uncomfortable down there.

If the tightenings become too uncomfortable have yourself a nice warm bath. Stay at home as long as possible, it's the best place for you to be.

Good luck and sending you speedy labour vibes