D & C (Dilatation and Curettage.)
Its called a "D and C" (D&C)
uterine agenesis
Curettage
Although, there is also the cervical cavity, but since you were asking for the "main" cavity, I would say it's the uterine cavity.
internal OS
Abrasion is the accidental scraping of tissue. One term for the deliberate scraping of tissue is shave biopsy; another very different type of scraping is curettage.
Nourished by glycogen rich uterine secretions. -Pearson Text Book
Gonorrhea
The uterine cavity is the inner space of the uterus where fertilized eggs implant and develop into fetuses during pregnancy. It is lined with a specialized tissue called endometrium, which thickens and sheds during each menstrual cycle if pregnancy does not occur. The uterine cavity plays a crucial role in supporting the growth and development of a fetus.
Murola
Fibroids are divided into different types, depending on the location. Submucous fibroids are found in the uterine cavity; intramural fibroids grow on the wall of the uterus; and subserous fibroids are located on the outside
The embryoblast spends approximately 72 hours in the uterine cavity before implanting. in that time, it cannot receive nourishment directly from the blood of the mother, and must rely on secreted nutrients into the uterine cavity, e.g iron and fat-soluble vitamins. - from wikipedia