Chances of Miscarriage after Heart Beat on Doppler

Does anyone know the risk % for a miscarriage, once a heartbeat is detected on a Doppler?  I went in for my 1st visit (8 w 5 d).  When I scheduled the appointment, the doctor said I would not get to hear the heartbeat.  After my exam, the doctor said my uterus felt "full", and got the Doppler.  Does "full" also mean "big"?

[Dr. Kokil Mathur]

Hi!
I am not sure what full meant—could be that the uterus was big. If the fetal heart beat is heard on dopplar, then chances of miscarriage are less. At times instead of the fetal heart beat, mother's heart beat is transmitted, giving a false result. If you have completed 8 weeks, you can go for a transvaginal (through vagina) ultrasound to see the size of sac, fetal poles, and fetal heart beat. This is more confirmatory. Presence of fetal heart beat on transvaginal ultrasound increases the chances of pregnancy carrying forward. Take care!