4 weeks old

So my LO is 4 weeks today. Ever since she was born she has always been a pretty good sleeper at night...at the beginning should would go 3-4 hours before waking to feed...of course I had to wake her up no later than 4 hours (doctors orders) but now she will sleep 5-7 hours before waking to eat, which is great! So when I think she is starting to wake up she will make grunting noises, Whimper (eyes still closed) and then is quite for a little while (10-15 minutes) then do it again...when she does this she isn’t making any early signs of hunger (licking lips, mouth movements etc....) and her eyes are still closed so was wondering if I should be getting her up to eat right when she’s starting to do all that or wait till she shows more signs of hunger. This morning she did that for about a half hour and then she started licking her lips (eyes were still closed) so I then got her up to eat. I feel like if I wait a tad longer than she will be more awake to eat but at the same time I don’t want her thinking I’m not feeding her....she only really started to cry when I was trying to get situated to feed because she knew what was about to happen...