My baby (7 weeks old) last feed was 7 hours ago. He was still sleeping and didnt cry for milk. Guess its ok right?

But need to check for any fever if having. Some babies starts to sleep through the night at a young age (few weeks old). No need to worry about this if he does sleep through the night. Babies when sick has loss of appetite too. Such as teething, stomach ache, stomach bloated etc. But your case should be sleep through the night.