DC Eating less frequently??

anls520

DD is 6 weeks old today and last week I was BFing every 2 hours, but for the past 2 days she's been eating every 3-4 hours and sleeping in between.  Could she have already gone through a growth spurt?  Is it normal for her appetite to change all of a sudden?  I feel like this is really screwing up my supply and am starting to worry!