9 week old fussing until picked up

jahugs

I know you can not let a baby "cry it out" until at least 4 months, but lately my son wil fuss and fuss until I pick him up.  He isn't crying, so I let him go a few minutes, but inevitably he won't stop fussing until I pick him up.  Sometimes he'll even stop when I hover over him right before I pick him up.  Don't get me wrong, I love that he needs me, but I don't want to start a bad habit either. He did get his vaccinations last Thursday, so maybe he is still feeling the effects of that?  Any ideas?