I have heard several different sounds with my doppler. The sound I find the easiest is my my heartbeat. It is a loud, steady sound in the 80s-90s (my heart rate runs a bit high) I can find my heartbeat in several places in my pelvis and abdomen.
Another sound I hear is a whooshing sound, like a quiet roar. I think this is placental blood flow. My doppler has a digital read-out and sometimes the roaring sound has a higher rate-130s to 160s. I suspect it is picking up JingleBell somewhere under the placenta.
When I do find JingleBell, the heartbeat is *much* fainter than mine. The rate is very fast (140s-170s). The sound is unmistakable. I often find JingleBell "next to" my own heart beat. I have to put a lot of gel on the probe and move it verrrrrry slowly. I don't really even move the probe itself, I just alter the angle of it until I have covered a 360 degree area then I move it a bit and do the big, slow circle with the probe in the same place again.
The uterus is still below the pubic bone most likely so I place the probe low low low. Literally right above the pubic bone. I have to stretch my skin taut with the other hand because I have a pooch
I angle the probe down towards my tailbone instead of up towards my bellybutton. Then I start rotating the probe in that circle I was describing earlier. If my bladder is full, I find the baby off to one side by a few inches. And I have to press down pretty firmly, like my doctor does.
When I first got my Doppler, I took it to the doctor's office to see if it was even sensitive enough to hear the baby so early. (It was a $200 one off eBay)My doctor had found JingleBell with his doppler the week before and it definitely sounded fainter and less distinct with mine a week later. BUT, I knew what to listen for. Could you ask your doctor to humor you and listen for your baby??
Try to enjoy playing with your new doppler. It is definitely NOT EASY to find a baby early. Relax, and know in your heart that your baby is in there, snug and safe and alive. Focus on familiarizing yourself with all the distinctive sounds you are hearing. I bet you will run across your sweet baby soon!
Here is a link to a sample of fetal heartbeat on a doppler: http://www.sonotraxfetaldoppler.com/record.html