I just wanna make it to 36 but now I'm worried

Kristyanne
Ok so anyone had anything similar please let me no 
I'm 32 plus 4 
Baby a is head down and I can feel her getting lower every day 
The last week Iv woken up and been unable to move with out rely sharp unbearable pain in my bikini line area 
My back hurts like crazy and I have light cramping in my belly 
Every time I stand and walk it feel like my pelvic bone is grinding and my lower back keeps clicking 
Should I be worried I have a doctor appointment in 4 days 
The doctors has already said given my history she is worried I won't make it to 34 weeks but I'm hoping to make it to 36-37 weeks :( as my sons first day of school is at the end of this month and I wanna be there Iv never missed any of my kids big days and I hate the idea of going early and missing my little man go to school