Your doctor should then instruct you on how to feel for the strings. Additionally, be sure that your doctor informs you of the type of IUD that was inserted (ParaGard or Mirena) and when it needs be replaced. Most doctors should give you a little card that you can put in your wallet with all of this information. If not, it is a smart idea to write down this information and keep it in a reliable place. This information is important should you switch doctors later on, as a health-care professional can not tell, just by looking, which IUD you have and when it was inserted (and, therefore, when it should be removed).