YES. It is important to clean your underwear every day because a dirty pair of underwear contains typically traces of fecal matter and bacteria that can spread all the way to your urinary tract, and then cause you a wide variety of infections, from fungal to UTI’s or Urinary tract infection.
To prevent these infections, ensure to clean your underwear EVERY DAY, using a good quality soap and air dry them. This helps to kill germs and keep them fresh always.