It's rare for a baby to ever be able to sleep too much during the day, so it really won't ever be a problem. Up to about 3-4 months, they should be sleeping at least 5-6 hours a day. And around 6 ish months, at least 3-4 hours a day. 6 week olds are very sleepy! My daughter was pretty much only waking to eat and otherwise sleeping all day. It changes a lot after 3 months, so enjoy it while you can and do some things for yourself while you still have a chance. Even at 6 months, she still sleeps probably 5 hours a day and still sleeps well at night.