My dog hasn't pooped since yesterday morning and he usually poops twice a day in the am and pm should I be worried?

Get a can of pumpkin, not pie filling- give him a tablespoon... works wonders for digestion in dogs- I give my dog pumpkin three times a week... if he doesn't go in a day or so or if he looks like he's straining or having a hard time call your vet... good luck