When a woman is not pregnant, the position of their cervix changes throughout the stages of their menstrual cycle.
For example during ovulation, the woman's cervix is higher in the vagina.
After ovulation and before menstruation, if the woman has not become pregnant, the cervix drops lower in the vagina.
After ovulation, your cervix will drop and harden.
The cervix may be low but stay soft as you get closer to menstruating.
And if fertilization didn't happen during ovulation, the cervix will open to allow menstruation to happen, but will stay low and hard.
The cervix is said to show infertile signs when it is low, closed, firm, and lying against the vaginal wall; that change occurs quickly under progesterone influence.
If the cervical length is less than 25 millimeters (short cervix) before 24 weeks of pregnancy and you're only carrying one baby, your doctor may consider a procedure that uses sutures or synthetic tape to reinforce your cervix (cervical cerclage).