So we bought a fetal doppler so that we could hear the baby's heartbeat anytime we want. It came in the mail right when we crossed into our 12th week and tried it immediately. We did find what we thought was the heartbeat, but it turns out it was actually just me. The next week, we absolutely found the heartbeat. We knew because it was super-fast!
Now, we have pretty much gotten the hang of finding it, as long as Pintsize cooperates. We look for the heartbeat one or two times a week now, and it has become a fun game for us. I lie on the bed propped on some pillows, and Jon looks for the heartbeat. He has been known to chase the baby all the way across my abdomen and back with the doppler wand. It's a really nice bonding activity for us, and I think it helps him feel more involved. I'm trying to be very aware of how men feel a little "left out" of the baby-growing process and am including him in as many of these kinds of experiences as possible. I want him to bond with our baby too.
So anyway, he will sometimes find the heartbeat for something like 2 seconds and then Pintsize will run away and hide. So he looks for it again! Sometimes we spend 30 or so minutes chasing the baby around trying to get to the heartbeat. I've made it into a game called "Find the Baby." We've recorded it on my phone a couple of times. It's so much easier to calculate the bpm when you do it from a recording rather than live. So here's a video I made using recorded heartbeat of our baby last night! I'm so excited when I hear this. It makes everything so much more real!