10 week old sleeping 9 hours at night

My nearly 10 week old has been sleeping 9 hours at night. This is not a brag, more of a worry. Should I be waking him for a feed? He’s gaining weight just fine. He has always been a good sleeper at night, doing 5-6 hour stretches from 3 weeks, but for the past week he has been sleeping 11pm-8am.