Baby is 13 weeks and 4 days and doesn’t smile much

He does smile but we have to work hard to get a smile out of him. Otherwise he always smile while looking up at his swing.

He doesn’t smile just randomly or with toys. He doesn’t play with toys either. Idk if I should be worried. All the babies in my moms group are smiling randomly and when I smile at them they smile back. When ppl smile at my son it’s just a blank face. Just wish he was happy.