Hey Rusty,
I am confused, is it like you hear two heart beats like a pulsing? could it just be bubbas pulse on another part of its body somewhere?
I reckon go and get it checked out if you think its different to normal though.

I'm sure its all fine, but if you get too worried, dont feel silly about getting it checked out, your a mum, its your job to worry and make sure everything is ok!!
xox