Why is my puppy not going potty?

I just got my first puppy today! whoo hoo! He's a cutie pie. A yorkie poo...anyway he hasn't gone potty all day! After he ate i took him right outside but he just cried becuase it was so cold. then he just ate a little more again and hasn't used the potty! I've had him since about 8:30pm and it's 3:00am now and he still hasn't pooped...He did pee a little in the car earluer but that's all!