I had the paragard in for 4 years. I could always feel my strings and nothing ever felt off with it, however I am now a little over 9 weks pregnant and at week 7 i had to get my paragard removed. I was lucky and it did not hurt my baby when it was removed. Im just saying that it does happen. There is no birth control that is sperm proof so if you have a iud I would still use a second form of bc.