For those of you who own a fetal doppler, have you experienced finding your baby positioned lower in…

For those of you who own a fetal doppler, have you experienced finding your baby positioned lower in your uterus? I'm finding that my son likes to hide in the lower right part of my uterus as i find his heartbeat located there 85 percent of the time. I'm gonna be 20 weeks tomorrow for some reason I thought it would be located higher by now.