Baby sleeping long

My 7 week old sleeps a minimum of 5 hour straight at night, but can sleep up to 8 hours. Is this normal? He used to wake us up to eat every 3 hours, but now he doesn't. We usually do his last feeding at midnight and then he wakes up when daddy wakes up for work 6am. But even then sometimes he sleeps longer and wakes up at 7/8am.