Have a PELVIC ULTRASOUND.
Id like to know the answer to this too I am 17 and after months of pain in my lower abdomon and months of not getting my period my gynocologist say my uterus is very thin probably because of the...
It is the lining of the uterine womb space/compartment
The lining of the uterus is what denigrates when your egg isn't fertilized and you get your period.
Like a paper
endometrium