Am I experiencing prelabour?

I am currently 40+4. For the past 3 days I have had constant lower back pain, constant menstrual like cramps (x10), and my whole belly and thighs just ache. I've been losing bits a pieces of my mucous plug. Baby has dropped very low as well. I can't stay I could even pin point contractions, but I have had moments where it feels as if I've pulled a muscle in my stomach or hips? I don't know what if that's right.. I am just so done with this pain. It doesn't seem to be letting up, and it's gotten slightly worse and started keeping me up at night. I'm not sure if this is all considered prelabour or if these are just normal overdue mama symptoms