This discharge is made up of secretions from the cervix and vagina, old cells from the walls of the vagina, and normal bacterial flora from the vagina.
You'll probably notice more vaginal discharge
as you approach labor
, although it's likely to look somewhat different from the flow you've become accustomed to.
In very early pregnancy, cervical secretions filled your cervical canal and created a protective barrier – the so-called mucus plug.