How much does he weigh? As a hatchling he doesn't need seconds and it's not unknown for ball pythons to be little pigs as they are opportunistic eaters. So they will want to take whatever they can get but that doesn't mean they should. Keep to your one week schedule otherwise you're going to have a chubby little guy :p
When in doubt follow this chart.
Edit: ack KevinK you beat me to it! How does everyone type so fast lol