Baby's behavior

Hey! My daughter will be 11 weeks tomorrow. Up until this week my daughter has been a very happy baby, giving lots of smiles and "conversation," rarely crying. This week she is quiet and reserved, looking at everything around her. She's also fussy and not very interested in play time. She's also cut her afternoon and evening naps from 1.5 hrs to just half an hour! Anyone else's kiddo a bit out of their element this week? Or go through something similar?