Fetal doppler

Michelle • Hi iv 3 boys and would like a girl. I`m 36 now and all my friends think I`m mad. I can`t bring myself to tell mum we r ttc she will hit the roof, but I`m so broody I don`t care xxx
So I bought angel sounds fetal doppler I'm 9 weeks 2 days I can't find the heart beat I keep finding mine and I think I can hear the placenta. Do u actually listen on the pubic bone or just above it? I'm scared something is wrong with my baby x