My 3 month old wont engage eye contact?

Hello there Im a mama to a baby boy and he is 3.5 months old... he does everything normal... great sleeper, smiles, coos but wont look into my eyes it will be for a few sec and then he will look away... he knows my voice and will start to smile but wont look at me... hes just looking around but cant focus.. im a bit concerned. did anyone else have this and there kids were ok?