You so need an u/s to see whats going on in there.
My money is on boy. :)
The various heart rates could be due to the baby's activity~ they have sleepy times and active times in the womb. Maybe the baby was falling asleep during this time!~Sarah :)
Oh I know that, BUT this was within a 2-4 second span! That's what made us say "Hmmm?" :)