My son crys & shakes when he wakes up from a nap?

My 22 month old after taking a nap when I'm home will wake up crying his head off & shaking like he's soooo upset. I thought maybe he was having nightmares but every time? He's been doing this for the past few weeks & only does it after he takes a nap. His dad who is with him Mon-Thu said he doesn't do that when I'm not home. He crys so bad that the only thing that will calm him down is a short car ride.