Hello and welcome to HCM
Passage of watery discharge at term (38 week) could be due to rupture of membranes
Subsequent passage of blood is of concern.
You should visit your gynaecologist without delay.
In case there is rupture of the membranes and if lasts for more than 24 hours, it could lead to infection known as chorioamniotis. This is infectious process involving the membranes. Antibiotica have to be started in this condition to control the infection.
Thanks and take care
Dr Shailja P Wahal