The cervix is the entrance of the uterus from which menstrual blood flows through a pin-sized hole into the vaginal canal. The cervix is cylindrical or conal in shape and is located in the upper part of the vagina. When touched, it feels like the tip of a nose. However, for some women, it moves significantly lower during menstruation. Since the cervix is usually relatively high in the vagina and the menstrual cup is placed low in the vagina, the cervix remains above the cup. But if the cervix is significantly low, it may be in the cup. Tampons on the other hand are placed further up inside the vagina, just where the cervix is located.
In Lunette diagrams, the cervix is intentionally placed very high to emphasize that the correct position of the menstrual cup is low in the vagina.
Leaks are more frequent for women whose cervix moves lower during menstruation or whose menstrual cup has been inserted too high in the vagina, next to the cervix, or above it. The menstrual cup might also exert pressure on the cervix and cause discomfort and even pain. The best way to evaluate the position of your cervix is leakage - if you have experienced leakage even when the cup has been opened, make sure that the cup is significantly lower than the cervix. In some women, the cervix fits best inside the menstrual cup.
For many women, the cervix descends after giving birth; for others, it is simply situated low in the vagina. If you have given birth recently or more than once, you should exercise the pelvic diaphragm muscles by doing kegels. Keeping these muscles in shape is useful when using the menstrual cup, as well as to avoid incontinence and improve sex.
If you have not experienced leakage and you have not located the cervix, there is no need to try to do so. You are one of the women whose cervix is so deep in the vagina that it does not affect the use of the menstrual cup in any way.