Baby in IFC

My baby is in IFC since 1st November at 3.5 months old, he's tuning 5 months soon in 1.5 weeks. Lately he's been more moody and less smiley. After we pick him up from IFC at about 6pm, he seems to be tired-looking and moody. He still smiles and laugh, but less as compared to weekends when he is with my parents. Should I be worried?