Apparently teeth can come this early, and it explains the last four days of hell. The euphoria of the first teeth did somewhat make up for it 🙂
The lower two teeth came in together, which means 18 more to go.
Update: The little guy is too young to understand how to use his teether. After a few days of chewing our fingers and hands with his sharp new teeth, we sucked it up and bought him the Sophie la Girafe teether. Best decision ever.