Should I be waking up my baby to eat?

Cindy • 25 yo. FTM to a Baby girl. Grace Elena<3
My baby will be 8 weeks Monday. I used to wake her up to feed every 2-3 hours before she turned a month. Now she usually wakes up on her own just in time for her feeding. However, there are times like today where she sleeps for 4 hours straight. She fell asleep at 8pm and it's now 11:55pm and she's still asleep. 
Normally she sleeps through the night with ou 1 feeding around 4am. Just wondering what everyone else is doing :)