Fetal Heart Doppler

My mom sent me a Sonoline B heart Doppler  and I LOVE it. So I know what the  babies heart beat sounds like and what my own sounds like( a swooshing sound) and another sound of what I think is the blood flow. But my question is, for those of you that have one, do you hear the babies heart beat on the left and right side of your uterus. My girlfriends say they have only ever heard theirs from one side or the other. I didn't have one of these with my other two kiddos who are 8&9 so I'm not too sure. I'm getting two heart beats. Right side is 184 Bpm and the left side is 168 Bpm. At my ultrasound at 8 weeks we only saw one baby with a heart beat of 182. I'm now 11 weeks. What are your thoughts? I miscarried is August due to blighten ovum. There were two empty sacs. We are taking our kids for a surprise ultrasound this weekend for them to find out we are pregnant. My husband keeps saying we are in for a surprise ourselves, there are two lol. Anyway I'm just curious if everyone hears two or not