Two month old only smiles occasionally

Hi moms,

My baby was born on 1/25/19. She turned two months on Monday and only smiles occasionally. Our pediatrician asked us if she smiled at us all the time and if she was cooing all the time but unfortunately our answer was “sometimes.” I’m a little worried. Any moms out there having the same issue. She definitely doesn’t smile all the time and doesn’t hold cooing conversations with us.

Any help or advice would be greatly appreciated. I’m worried my baby is behind 😢