Heartbeat by hairline?

Kay • Momma of 3!🤴🏼🤴🏼 👸🏻
Expectant mommas; 
I'm currently 19w1d with baby #3. I had an appt yesterday & doctor was using the doppler to find my little girls heartbeat. She was looking to the side of my belly button and nothing. I told her I still feel her very low. Well sure enough, her heartbeat was found below my underwear/hair line. I don't remember my first two pregnancies being that low half way into pregnancy. This little one seems to be applying a lot of pressure from her sitting low. Haven't had an ultrasound since 12w and next one isn't until my anatomy scan at 21w. Any other mommas carrying that low with no concerns?