Mucus discharge - TMI

Ok so I went to the Doctors last week and the doctor told me that I’m probably going to miscarry. The doctor saw a fetus (they hadn’t the week before) but no heartbeat and he said I should have at that point (8+ weeks). I’ve had no miscarriage symptoms. I have had some mucus discharge recently but just had this discharge which is more of a tissue. Is this the start of a miscarriage?