Is it normal for a 7 week old to suddenly sleep a lot? Most days he eats every 3 hrs. sometimes…

Is it normal for a 7 week old to suddenly sleep a lot? Most days he eats every 3 hrs. sometimes after he falls back to sleep and sometimes he will stay awake for 2 hrs smiling and stuff then sleep for an hour. Well last night he wouldnt go to sleep until around midnight and slept all the way till 8am. Then woke up, I changed him and fed him and he fell right back to sleep. Woke up again at 10:30am and I change him and fed him and he didnt eat his whole bottle and fell back to sleep again, still sleeping at 11:30 am