Growth Spurt At 7 Weeks?

Is there a growth spurt during 7 weeks of age? I found my newborn been sleeping more and instead of drinking her fm of 100ml on regular basis, she's only drinking 30-50ml and only 1 feed is at 100ml throughout the whole day. And probably due to less milk intake, she didn't poop (she poops once daily). And I realized she's extremely sleepy. She would reject the bottle and with a few rock, she fell asleep right away. Is she going through a growth spurt now?