Although, there is also the cervical cavity, but since you were asking for the "main" cavity, I would say it's the uterine cavity.
The abdominal cavity.
The endometrial cavity is the inside space of the uterus where the endometrium, the lining of the uterus, grows and thickens during the menstrual cycle. This cavity is where a fertilized egg implants and grows during pregnancy. Changes in the endometrial cavity are monitored in procedures like ultrasounds and hysteroscopies to assess the health of the uterus.
ventral cavity
The pelvic cavity.
yes
vagina
Uterus
The abdominal cavity would have to be opened to remove the uterus or womb through a surgical procedure known as a hysterectomy.
abdomen
Uterus belongs to a female. It is situated inside the lower abdomen in the pelvic cavity.
The uterus is in a woman's lower abdomen, above her pelvis.
pelvis, if not pregnant.