How long is too long

This is the weirdest thing EVER. I tend to be a let the baby sleep Mom but my ebf babies never slept more than 3-4 hours. So how long is too long. Yes she has has plenty of wet and dirty diapers and she really did not nap yesterday AT ALL. She did sleep for maybe 4 hours total (15 mins here and there and then an hour in the evening while at Grandma's). So yeah at 7.5 weeks how long do you let pigger sleep??