Guy walked by and heard my baby's heartbeat

DeShawn • Almost 23. First time mommy. And doing it all on my own! Due January 2017! ☺️
Tonight at work something pretty cool happened. This Native American guy that works in the back, I don't really talk to him much, he stays quiet most the time, but tonight he walked past me and then turned around and pointed at me. He was like "Two heartbeats?" I'm like huh?! What you talking bout? He then repeats himself "two heartbeats." I'm like oh I'm pregnant and he gets this huge smile and said that's it! And walks away.
We work together all the time but I've never had a full conversation with him since he's so quiet and to himself so I'm pretty sure he wouldn't know I was pregnant otherwise. For him to randomly say this to me really made my night.