My dog hasnt peed all day..?

she is a one year old miniature weiner dog. She has been drinking water and eating but she hasnt peed outside or inside all day ( 17 hours ) Its not because we arnt taking her outside because we have been alot today and she would go in the house anyway. She hasnt peed anywhere we dont know about because she has been in my sight all day. She is pooping, playing, eating, and drinking fine. Also she doesnt have any emotional problems. What could be wrong?