During pregnancy, the cervix secretes mucus to form a thick plug. This seals the cervix during pregnancy, acting as a barrier that prevents bacteria from entering the uterus.
As labour approaches, the cervix thins and dilates, enabling the mucus plug to come out sometimes as a whole or simply as increased vaginal discharge over the course of a few days.
Some women do not notice the plug dislodging while others experience the early signs of labour before it is released.
The plug can be clear or cloudy and is often streaked with blood (known as a 'bloody show'). This is simply where the movement causes small capillaries to break and is quite normal.
Sometimes a vaginal exam or sexual intercourse can dislodge the plug resulting in some bloody discharge.
The loss of the mucus plug is a sign that the body is beginning to prepare for labour but it can be anything from a few hours to two weeks before true labour begins.
If you notice blood tinged mucus prior to your 36th week of pregnancy, notify your doctor or midwife so that they can check whether the onset of an early labour is likely.