Evelyn started sleeping through about 3weeks so I wouldn't say it's unusual. I woke up in the morning with HUGE breasts for a few days, then they settled down. If your LO carries on missing a feed through the night, your body will stop producing it but your supply must be good as he's getting a good feed before bed and sleeping through.
Oats are good to increase milk supply so if you're worried get some porridge :-D I have it every morning. Xx