13 weeks

Mike brought the kids to the doctor to hear the baby's heartbeat.  When we were talking about it later, I realized the kids have never heard any heartbeat before.  They have no idea what their own heartbeat sounds like, so I had them try and decribe what they thought the baby heartbeat sounded like.  Michael said it sounded like a train and added, "I even thought I heard a little, CHOO CHOO!"