First off - take a deep breath!!
Stress will not help you or your baby. You are hearing a heart-beat that's a good thing. You have a doppler at home - wow!
Every pregnancy is different. Some babies stay in the back of the uterus. Others, right up front.
The fact that you are being seen, basically, every two weeks - you are stressing over things you have no control over!!! The stress is not helping you at all.
I had five pregnancies and lost 3 of those - one at 19 weeks and the other two at 12 to 14 weeks. You don't state why you are in a high-risk pregnancy nor how many live births you have had. But bottom line? DO NOT stress - you can hear a heartbeat? The baby MAY be in the back of your uterus.
I hope that all goes well for you in this pregnancy!! Please do not stress - you are not helping yourself or your baby!!
Best,
Cheryl