Baby's heart beat with Doppler at 12 weeks

I went for my 12 weeks appointment today for my fetal heart beat check which I'm always nervous about because I had a miscarriage last year at 8 weeks. Today my doctor used a Doppler and she couldn't find my baby's heart beat, so naturally I began to panic so the doctor tried to calm me down and then she decided to get me in for a sonogram. My baby was wiggling and a strong heart beat at 162. The sonogram tech and the doctor said that the reason she had a hard time with Doppler was because the baby is still under my pubic bone. So I'm going back in 2 weeks for another heartbeat check. So is it normal to have my baby so low at 12 weeks?